3DS App Manager

A Nintendo 3DS homebrew application for managing installed titles: install CIA files, back up save data, uninstall titles in batch, and view system information — all from a single clean multi-screen interface, built for consoles with a large, cluttered library.

Select as many titles as you want on one screen, get an automatic offer to back up (and later restore) their save data, and let the app confirm each deletion actually happened before moving on — instead of picking through the HOME menu one title at a time.

Why

The HOME menu only deletes one title at a time and has no built-in way to back up a save before the title disappears with it. 3DS App Manager turns that into a batch operation with the backup step made explicit and automatic — optional per run, or forced on always from Settings — so cleaning up storage never has to mean gambling with save data.

Download

Grab the latest build from the Releases page.

Download 3ds-app-manager.3dsx from the latest release.
Copy it to /3ds/ on your SD card.
Launch it from the Homebrew Launcher.
Wait for the loading screen (a progress bar shows while titles are read).
You land on the Main Menu — pick a feature and get started.

Requirements: Nintendo 3DS / 2DS / New 3DS running Custom Firmware (e.g. Luma3DS) or a homebrew entrypoint with sufficient AM access.

Features

Install

Browse the SD card for .CIA files and install them one at a time or an entire folder in a single pass.

Browse the SD card file system to find .CIA files
Install single files or batch-install an entire folder in one step (Y)
Detects Update (^) and DLC (+) types at scan time — no extra file reads
Size shown right-aligned per row; type badge close to size column
All installs always target the SD card

Backup Saves

Back up any title's save data on demand, independent of uninstalling it — so a backup can be refreshed anytime, not just right before deletion.

List all installed titles with backup status at a glance ([ ] none · [*] exists · [X] selected)
Select individual titles or back up the entire library at once (Y)
Three save archive types per title: User Save, ExtData, Boss ExtData
Backup date shown in the bottom-screen detail panel
Backups stored under [backup_path]/[TitleID]/

Uninstall

The core flow: select as many titles as you want and delete them in one batch, with an automatic offer to back up save data first.

Multi-selection with A; batch uninstall with X
Optional pre-uninstall backup (prompted automatically, or forced via Settings)
Selected titles list visible on the bottom screen throughout the confirmation flow
Automatically finds and offers to delete related DLC/Updates for base games
Post-delete verification: slot is cleared only after AM confirms deletion

System Info

A per-category browser for everything installed, with backup/restore/delete actions available straight from a title's detail page.

Overview: Games / Updates / DLC counts + total sizes + SD free space
Navigate into each category (A) to browse the full title list
Per-title detail page with full name, Title ID, version, size, storage location, backup date
Actions per title: Backup Save Data, Restore Save Data, Delete Title

Settings

Six toggles/options, all applied and saved as soon as you change them — no separate save step.

Setting	Default	Description
Force Backup	OFF	Auto-backup before every uninstall (no prompt)
Skip Uninstall Confirm	OFF	Delete immediately on X without confirmation
Force Restore	OFF	Auto-restore backup after every CIA install
Skip Install Confirm	OFF	Install immediately on A without confirmation
Backup Folder	`sdmc:/3ds/3ds-app-manager/backups`	Cycle through 5 preset paths with left/right or L/R
Language	System language (EN/IT, else EN)	Cycle between English and Italian for all app UI text

Changes are saved in real time; press B or START to return to the menu.

General

Shared behavior across every screen:

Sort by Name, Size (largest first), or Title ID
Filter by All, Updates only, or DLC only
Supports up to 500 titles (HOME menu cap is 300; counter turns red above it)
Multi-language title names: system language → English → Japanese → any available
Hold SELECT for a full controls overlay (flicker-free rendering)
Sleep mode compatible — close and re-open the console freely
Progress bar during title loading

How to Use

Install CIA

From the Main Menu, select Install CIA and press A.
Navigate the file browser with the controls listed in the Controls Reference section.
Directories appear in cyan with a [DIR] prefix. .CIA files show size right-aligned and a type badge: ^ = Update, + = DLC.

Installing a single file:

Navigate to the .CIA file and press A.
Confirm the prompt (skipped if "Skip Install Confirm" is ON in Settings).
Wait for the progress bar to complete.

Batch installing a folder:

Enter the folder containing your .CIA files.
Press Y. The app installs all files one by one and shows progress for each.

All installs target the SD card. NAND installs are not supported.

Backup Saves

Each row in the list shows:

[ ] — no backup exists
[*] (green) — backup exists
[X] (yellow) — title selected for batch backup

The bottom screen shows full name, Title ID, size, storage location, and last backup date for the cursor item.

Single title: navigate to it -> press A to select -> press X to back up.
Multiple titles: press A on each -> press X to back them all up.
Entire library: press Y — no selection needed.

For each title, the app saves up to three archive types:

savedata/ — main game saves
extdata/ — extended data (e.g. DLC content)
boss_extdata/ — SpotPass / StreetPass data

A backup_info.txt file with title name, version and date is included in each backup folder.

Uninstall Titles

Use up / down to navigate (or left / right to jump a full page).
Press A to toggle selection (checkbox turns yellow when selected).
Use L / R to cycle sort modes (Name -> Size -> ID); Y to filter (All -> Updates -> DLC).
Press X to begin the uninstall flow.

The uninstall flow:

Step	Prompt	Actions
1 — Backup?	Back up before deleting?	A = yes · B = skip · START = cancel
2 — Backup path	(shown only if backup chosen)	A = use default · Y = pick from preset list
3 — Related titles	DLC/Updates found for base game	A = include · B = skip · START = cancel
4 — Final confirm	Review list on bottom screen	A = confirm · B = cancel
5 — Deletion	Progress shown per title	automatic

If "Force Backup" is ON, step 1 is skipped and backup always runs.
If "Skip Uninstall Confirm" is ON, step 4 is skipped.

System Info

Overview screen: shows Games / Updates / DLC counts and sizes, plus SD free space.
Press up / down to navigate categories; A to enter a category.

Category list: lists all titles with name and size. Press A on any title to open its detail page.

Title detail page:

Full name, Title ID, version, size, storage location, backup date
Related Updates and DLC (for base games)
Three actions (navigate with up / down, execute with A).

Action	What it does
Backup Save Data	Saves all archive types to the backup folder
Restore Save Data	Restores save data from the last backup
Delete Title (+ related)	Removes the title, its DLC, Updates and all save data

Restoring a save: System Info -> find the title -> A -> "Restore Save Data" -> A.

Settings

Navigate with up / down. Change a value with A, L, R, or the d-pad left/right.
The bottom screen shows a description of the highlighted setting.

Settings are saved in real time. Press B or START to return to the main menu.

Controls Reference

Main Menu

Button	Action
Up / Down	Navigate menu
A	Enter selected screen
START	Exit application
SELECT (hold)	Show context-sensitive help overlay

Uninstall Screen

Button	Action
Up / Down	Move cursor one row
Left / Right	Jump one page
A	Toggle title selection
X	Start uninstall flow for selected titles
L / R	Cycle sort mode (Name -> Size -> ID)
Y	Cycle filter (All -> Updates -> DLC)
SELECT (hold)	Show context-sensitive help overlay
B	Back to main menu
START	Exit application

Install Screen (File Browser)

Button	Action
Up / Down	Move cursor
Left / Right	Jump one page
A	Enter folder / Install CIA file
Y	Install all CIA files in current folder
B	Go up one folder level

Backup Screen

Button	Action
Up / Down	Move cursor one row
Left / Right	Jump one page
A	Toggle title selection
X	Backup selected titles
Y	Backup all titles
L / R	Cycle sort mode
SELECT (hold)	Show context-sensitive help overlay
B	Back to main menu

System Info Screen

Button	Action
Up / Down	Navigate categories / title list
A	Open category list / open title detail
L / R	Cycle sort (in category list)
SELECT (hold)	Show context-sensitive help overlay
B	Back / back to overview

Title Detail (from System Info)

Button	Action
Up / Down	Select action
A	Execute selected action
B	Back to category list

Settings Screen

Button	Action
Up / Down	Navigate settings
A / L / R / d-pad left-right	Change value
SELECT (hold)	Show context-sensitive help overlay
B / START	Save and return to menu

Screen Layout Reference

Top Screen — Uninstall

+-----------------------------------------------------+
| Uninstall                                           |  <- header
| T:120  Sel:3  Sort:Name  [All]                      |  <- info bar
| [ ] Super Mario 3D Land             0004000000...   |
| [X] Pokemon Sun              ^      0004000000...   |  <- selected, Update
| [ ] Mario Kart 7 DLC         +      0004008C00...   |  <- DLC
| A=Sel  X=Delete  L/R=Sort  Y=Filt  B=Menu  SEL=Help |
+-----------------------------------------------------+

Symbols: ^ = Update (cyan), + = DLC (green)
Checkbox: [ ] unselected, [X] selected (yellow)

Top Screen — Install (File Browser)

+-----------------------------------------------------+
| Install CIA                                         |  <- header
| sdmc:/roms/cias/                                    |  <- current path
| [DIR] demos/                                        |
| SuperMario.cia                        ^ [45.3 MB]   |
| DLC_Pack.cia                          + [12.1 MB]   |
| A=Enter/Install  Y=All  B=Up  DX/SX=Page            |
+-----------------------------------------------------+

Top Screen — System Info (Overview)

+-----------------------------------------------------+
| SYSTEM INFORMATION                                  |
|                                                     |
|   Games:      87    4.23 GB                         |
| > Updates:    43    980 MB                          |  <- cursor row
|   DLC:        31    1.12 GB                         |
|                                                     |
|   SD Free: 12.4 GB / 59.6 GB                        |
+-----------------------------------------------------+

Tips & Tricks

Free up the most space

Go to Uninstall Titles.
Press R twice to sort by Size (largest first).
Select the titles you no longer need and press X.

Clean up only DLC and Updates

Press Y once for Updates, twice for DLC.
Select what you want to remove and press X.

Check what has a backup
Open Backup Saves. Titles with [*] in green already have a backup; [ ] means never backed up.

Batch backup before a big cleanup
Go to Backup Saves -> press Y to back up everything, then proceed to Uninstall Titles.

Restore a save after reinstalling a game
Reinstall the .CIA from Install CIA.

If "Force Restore" is ON, the backup is restored automatically.
Otherwise: System Info -> find the title -> A -> "Restore Save Data".

FAQ & Troubleshooting

No titles showing up
The app only shows user-installed titles. System titles are filtered for safety.

The title counter is red
You have over 300 titles. The HOME menu cap is 300. The app still shows all of them (up to 500) — consider cleaning up.

How do I restore a backup?
System Info -> navigate to the title -> A -> "Restore Save Data".

Where are my backups?
[backup_path]/[TitleID]/. Default: sdmc:/3ds/3ds-app-manager/backups/. Change in Settings.

Is it safe to delete updates or DLC?
Yes. Each is an independent title. Deleting an update reverts the game to its base version.

Can I use this without CFW?
A homebrew entrypoint is required. Full title deletion requires AM access (CFW recommended).

Scroll feels slow
Single press = one row. Use left / right for page jumps. The deliberate speed prevents accidental skips.

Cannot find a title
Try different sort modes (L / R) or use the filter (Y) to isolate Updates or DLC.

Something deleted but still showing in HOME menu
Restart the HOME menu or the console. The 3DS system cache can take a moment to update.

Problem	Solution
App will not load	Make sure you are on a recent Homebrew Launcher and have CFW access
Loading bar appears stuck	Not stuck — it reads each title individually. 200+ titles can take ~30 seconds
Backup failed	Check that the SD card has enough free space and the backup folder is writable
Install failed	Verify the `.CIA` file is not corrupted; check free SD space
Restore failed	The backup folder may be missing or the title must be installed first

Safety

System titles filtered — ranges 0x00040010, 0x00040030, 0x00040138 are excluded
Confirmation dialogs before every destructive action (unless disabled in Settings)
Post-delete verification via AM_GetTitleInfo — title removed from list only after system confirms deletion
Backups are independent — deleting a title does not delete its backup

Backup Structure

[backup_path]/
|__ [TitleID]/            e.g. 0004000000033500/
    |__ backup_info.txt   metadata (date, version, name)
    |__ savedata/         main game saves
    |__ extdata/          extended data (DLC content)
    |__ boss_extdata/     SpotPass / StreetPass data

Default backup_path: sdmc:/3ds/3ds-app-manager/backups
The path is overridable at build time: -DDEFAULT_BACKUP_PATH="..." (used by host tests).

Alternative paths (cycle with d-pad left/right in Settings):

sdmc:/3ds/3ds-app-manager/backups
sdmc:/backups/3ds-titles
sdmc:/save-backups
sdmc:/3ds-backups
sdmc:/backups

Configuration

Config file: sdmc:/3ds/3ds-app-manager/config.ini

backup_path=sdmc:/3ds/3ds-app-manager/backups
force_backup=0
skip_uninstall_confirm=0
force_restore=0
skip_install_confirm=0

Building from Source

Prerequisites

# Install devkitPro — see https://devkitpro.org/wiki/Getting_Started
sudo dkp-pacman -S 3ds-dev

Environment variables (add to ~/.bashrc or ~/.zshrc):

export DEVKITPRO=/opt/devkitpro
export DEVKITARM=$DEVKITPRO/devkitARM

Running Tests (host)

Unit tests compile and run on the development host without a 3DS or devkitARM:

make -C tests

Five binaries, no 3DS hardware required: formatSize/sanitizeName (test_utils), config round-trip (test_config), comparators/safety filter/smdhSelectName/filter logic (test_titles), the backup/restore archive-copy logic (test_backup, via a small in-memory fake FS_Archive in tests/shims/fake_fs.h that actually exercises copy/failure/cleanup behavior) and CIA header parsing/folder scanning (test_install). See CLAUDE.md's "Test coverage" section for exactly what is and isn't exercised this way — UI-driven code (draw.c, input.c's blocking flows) and the real AM install/delete calls still need on-device verification.

Build

git clone https://github.com/Marcogn/3DSAppManager.git
cd 3DSAppManager
make clean && make

Output: 3ds-app-manager.3dsx, 3ds-app-manager.elf, 3ds-app-manager.smdh

Error	Fix
`3ds.h: No such file or directory`	`sudo dkp-pacman -S libctru`
`Please set DEVKITARM in your environment`	Export `DEVKITARM` as above
Linker errors	`make clean && make`

Technical Reference

Language: C (modular architecture)
SDK: libctru (devkitARM)
Graphics: citro3d + citro2d (hardware-accelerated, flicker-free double buffering)
Services: AM (title management), FS (file system / save archives)
Target: Nintendo 3DS, New 3DS, 2DS (all variants)

Architecture

The application is structured into 9 modules for maintainability and testability:

source/
├── types.h            — Type definitions, enums, structs, constants
├── globals.h/c        — Shared global state (externalized from main.c)
├── utils.h/c          — Utility functions (createDirectory, formatSize, etc.)
├── config.h/c         — Config load/save (INI parsing)
├── titles.h/c         — Title loading (optimized), sort/filter, backup-dir helpers
├── backup_restore.h/c — Save backup, restore, title deletion
├── install.h/c        — CIA scanning and installation
├── draw.h/c           — All rendering functions (~790 lines)
├── input.h/c          — Input handlers and blocking flows (~580 lines)
├── lang.h/c           — UI string translation (English / Italian)
└── main.c             — Entry point + main loop (135 lines)

No Makefile changes required: the devkitPro template's $(wildcard $(dir)/*.c) includes all .c files automatically.

Module Relationship Diagram

main.c
  ├── globals.h/c        (shared state — all modules read/write via extern)
  ├── config.h/c         (INI parse/save — reads/writes globals.config)
  ├── titles.h/c         (loadTitles, sort/filter — reads/writes globals.titles[])
  │     └── [draw.h]     (calls drawLoadingScreen during load — forward-declared)
  ├── draw.h/c           (all rendering — reads globals, calls titles helpers)
  ├── input.h/c          (input + blocking flows — calls draw, titles, backup, install)
  │     ├── backup_restore.h/c  (save backup, restore, delete — calls draw for dialogs)
  │     └── install.h/c         (CIA scan, install — calls draw for progress)
  └── utils.h/c          (pure helpers — no globals, no 3DS services; host-testable)

lang.h/c  ─── T(id) string lookup, called from draw.c/input.c/backup_restore.c
              (reads globals.config.language; no other module dependencies)
types.h   ─── included by all modules (type definitions shared everywhere)

App State Machine

typedef enum {
    APP_MAIN_MENU,
    APP_INSTALL,
    APP_BACKUP,
    APP_UNINSTALL,
    APP_SYSINFO,
    APP_SETTINGS
} AppState;

The main loop dispatches draw calls and input handlers based on appState. Blocking flows (uninstall dialog chain, install progress, backup progress) run as sub-loops before C3D_FrameBegin to avoid nested frame management.

Core Data Structures

typedef struct {
    u64            titleID;
    char           name[256];     // truncated for list view
    char           fullName[256]; // used in detail views
    FS_MediaType   mediaType;     // MEDIATYPE_SD or MEDIATYPE_NAND
    bool           selected;
    bool           isValid;       // false after successful deletion
    u16            version;
    bool           hasBackup;
    C2D_Image      icon;          // reserved, not currently loaded
    bool           iconLoaded;
    u64            size;
} TitleInfo;

typedef struct {
    char backupPath[256];
    bool forceBackup;
    bool skipUninstallConfirm;
    bool forceRestore;
    bool skipInstallConfirm;
} Config;

typedef struct {
    int idx;    // selected category (0=Games, 1=Updates, 2=DLC, 3=System)
    int cursor; // selected row within the category list
} SysInfoDetailState;

typedef struct {
    char name[256];
    bool isDir;
    bool isCIA;
    u64  size;
    u64  titleID; // cached at scan time; 0 for dirs or unreadable CIAs
} FileEntry;

Rendering Pipeline — when frames are managed

The app has two rendering modes that must never overlap:

Normal frames (main loop):

aptMainLoop()
C3D_FrameBegin(C3D_FRAME_SYNCDRAW)
  C2D_TextBufClear(dynamicBuf)
  C2D_TargetClear(top, CLR_BG)
  C2D_SceneBegin(top)     → draw top screen content at z ≈ 0.5
  C2D_TargetClear(bottom, CLR_BG)
  C2D_SceneBegin(bottom)  → draw bottom screen content at z ≈ 0.5
  [if SELECT held: drawHelpOverlay() draws at z = 0.7 — NO second SceneBegin]
C3D_FrameEnd(0)

Blocking flows (install progress, backup progress, uninstall dialog chain, SysInfo detail) run before C3D_FrameBegin in the main loop and manage their own frames:

runInstallFlow() / runBackupFlow() / runUninstallDeleteFlow() / runSysInfoDetailFlow() {
    while (aptMainLoop()) {
        C3D_FrameBegin(C3D_FRAME_SYNCDRAW)
            drawFileBrowserScreen() / drawBackupScreen() / drawDialog() / drawTitleDetails()
        C3D_FrameEnd(0)
        hidScanInput(); handle input; break when done
    }
}

Rule — never violate: C2D_SceneBegin must be called exactly once per target per frame.
A second call on the same target clears it and causes flickering.
Overlays (SELECT help) must be drawn into the already-active scene at higher z-depth (0.5 → 0.7).
drawLoadingScreen and drawInstallProgressScreen each call C3D_FrameBegin/End themselves —
they must never be called from inside an already-open frame.

Title Loading & Language Fallback

AM_GetTitleCount for SD + NAND
AM_GetTitleList fills a u64 array of title IDs
Safety filter: skip ranges 0x00040010, 0x00040030, 0x00040138
AM_GetTitleInfo -> size, version, media type
SMDH icon handle -> UTF-16 short description extracted

UTF-16 -> UTF-8 with language fallback:

1. System language (cfguGetSystemLanguage)
2. English (index 1)
3. Japanese (index 0)
4. All 12 SMDH language slots
5. Fallback: "Title [TitleID]"

Clamp to MAX_TITLES (500); call sortTitles()

Names consisting only of spaces or -- are rejected and the next fallback is tried.

Sort & Filter Internals

static int filteredIndices[MAX_TITLES]; // indices into titles[]
static int filteredCount;

updateFilteredList() rebuilds filteredIndices by iterating titles[] (only isValid == true entries) and applying currentFilterMode. sortTitles() sorts titles[] in-place via qsort with one of three comparators (name, size, titleID).

Memory Budget

Allocation	Size
`titles[500]`	~120 KB
`filteredIndices[500]`	~2 KB
`fileEntries[256]`	~70 KB
`dynamicBuf` (text buffer)	4 KB
`sysInfoSubIndices[500]`	~2 KB
Total approx.	~200 KB

The 3DS homebrew heap is typically 32-64 MB — well within budget.

UI Layout Constants

Element	x	y	scale
Header bar	0	0	—
Header text (all screens)	4	4–6	0.54f
List rows (all screens)	varies	32 + i × 14.5	0.38f
Type badge ^ / + (all list screens)	240	row y	0.44f
TitleID right-aligned (Uninstall/Backup)	292	row y	0.38f
Size right-aligned (Install)	396 − len × 5.7	row y	0.38f
Size right-aligned (SysInfo)	396 − len × 5.7	row y	0.38f
Bottom hint bar	0	222	—
Bottom hint text	4	224	0.52f
Detail panel — name	4	22	0.52f
Detail panel — ID (`ID: XXXXXXXXXXXXXXXX`)	4	42	0.52f
Detail panel — version + size + location	4	60	0.52f
Detail panel — backup status	4	78–80	0.52f

Known Limitations

Icon images (C2D_Image icon) are allocated in TitleInfo but not loaded at runtime (complexity vs. benefit tradeoff).
Max file size per backup copy: MAX_FILE_SIZE = 100 MB.
Title name truncation: 32 chars in list views; full name shown in all detail/bottom panels.
Sleep mode: aptMainLoop() returns false during sleep, pausing the main loop. No aggressive frame-skipping permitted — rendering must continue every frame when awake.

Documentation

CHANGELOG.md — what shipped in each release
CLAUDE.md — contributor/architecture guide: conventions, test coverage, backup/deletion invariants to preserve, build notes
TODO.md — known technical debt and potential optimizations

Contributing

This is a personal project built primarily for single-user use, so there's no public feature roadmap open to proposals. Bug reports and small, focused fix PRs are welcome — open an issue before working on anything substantial to avoid wasted effort. Most changes should also come with a CHANGELOG.md entry and, where it's testable on host (see CLAUDE.md's "Test coverage" section), a test under tests/.

About this project

3DS App Manager is an independent project, built by Marcogn in close collaboration with Claude, Anthropic's AI coding assistant — Claude wrote and reviewed most of the code, under direct human design and review at every step.

Disclaimer

Use at your own risk. Always keep additional backups of important save data before uninstalling titles. The authors are not responsible for any data loss.

License

MIT, see LICENSE.

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
romfs		romfs
source		source
tests		tests
.gitignore		.gitignore
3ds-app-manager.3dsx		3ds-app-manager.3dsx
CHANGELOG.md		CHANGELOG.md
CLAUDE.md		CLAUDE.md
LICENSE		LICENSE
Makefile		Makefile
README.md		README.md
TODO.md		TODO.md
icon.png		icon.png

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3DS App Manager

Why

Download

Features

Install

Backup Saves

Uninstall

System Info

Settings

General

How to Use

Install CIA

Backup Saves

Uninstall Titles

System Info

Settings

Controls Reference

Main Menu

Uninstall Screen

Install Screen (File Browser)

Backup Screen

System Info Screen

Title Detail (from System Info)

Settings Screen

Screen Layout Reference

Top Screen — Uninstall

Top Screen — Install (File Browser)

Top Screen — System Info (Overview)

Tips & Tricks

FAQ & Troubleshooting

Safety

Backup Structure

Configuration

Building from Source

Prerequisites

Running Tests (host)

Build

Technical Reference

Architecture

Module Relationship Diagram

App State Machine

Core Data Structures

Rendering Pipeline — when frames are managed

Title Loading & Language Fallback

Sort & Filter Internals

Memory Budget

UI Layout Constants

Known Limitations

Documentation

Contributing

About this project

Disclaimer

License

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