Shows one folder
Point it at a folder — internal storage, an SD card, a USB stick. It reads that folder and nothing else, and notices when you add photos to it.
Android 5.1 and up · 3.1 MB · GPL-3.0
The tablet in your drawer still works.
It turns on. The battery is tired and the browser gave up years ago, but the screen is fine. RetroFrame is a free, open source app that turns an old Android tablet into a digital photo frame — pointed at one folder, showing your photos, asking nothing of you.
No account. No cloud. No analytics. The app doesn't have the
INTERNET permission, so it can't phone home.
—
—
Live preview — that's the real clock. Tap the screen.
Before you install it
This build has never run on a physical tablet. It compiles, passes 30 unit tests, minifies cleanly and passes lint — but a green build only proves the code is well-formed, not that a 2014 storage provider behaves the way it assumes. It's published so that it can be tested.
Every known defect is written down in the open, including that one.
What a tablet photo frame needs to do
Photos and video
JPEG, PNG, GIF, WebP, HEIC. MP4, MKV, WebM, MOV — muted by default, played to the end, then it moves on.
Wakes and sleeps
Screen on at 07:00, big clock and screen off at 23:00. It restarts itself after a power cut, which is the failure mode a shelf device actually has.
Favourites
Tap the heart and that photo comes around about three times as often — spaced out, so it never repeats back to back.
Gets out of the way
Fullscreen, no status bar, no navigation bar. Controls stay hidden until you touch the screen, then leave again.
Built for 1 GB
The target is a 2015 tablet with slow storage and a single hardware video decoder, not a phone that happens to run it.
The photo frame running on a real tablet
Captured on a 1280×800 tablet — the panel this app was written for.
How to turn an old tablet into a photo frame
Four steps, about ten minutes, most of which is finding the cable.
-
1
Put the photos on the tablet
Plug it into your computer and pick File transfer on the tablet when the USB notification appears — otherwise the computer only sees a charging device. Then copy your photos into
Pictures.An SD card works too, and is ideal: it keeps the photos off the small internal storage, and you can pull the card out to change the collection later.
-
2
Install the APK
Copy it across and open it, allowing installation from unknown sources when asked. Or over USB:
adb install -r retroframe-v0.2.0.apk -
3
Pick your folder
RetroFrame explains what's about to happen, then opens Android's folder browser already inside
Pictures. Open your folder, tap Use this folder, then Allow. It keeps permission to that one folder — not to your files in general.If Android says "Can't use this folder", you've selected the top level of storage or the Downloads folder — it blocks both for every app. Open a folder inside it, or put your photos in
Pictures. -
4
Set the schedule and leave it
Tap the screen, open settings, set a wake and sleep time in 24-hour
HH:mm. Turn on auto-start so a power cut doesn't leave a black screen. Then put it on a shelf and forget about it.
Two things worth knowing about the hardware
Heat kills batteries. A tablet permanently charging with a bright screen runs hot, and the battery will swell over months. Use the sleep schedule, turn the brightness down, give it air. If you can run it with the battery removed, do.
Turn off the lock screen, or the wake schedule lands on it instead of your photos.
How it's built
Version 0.2.0 was a rewrite. The features didn't change; how they work did. These are the measurements that drove it.
BeforeAfter
Scanning a 500-photo folder
~1,500 IPC calls
1 cursor query
Watching that folder
Full rescan, every 10s, forever
ContentObserver
Concurrent video decoders
Up to 3
1, shared
Image decode size
Fixed 2048×2048
Your screen, RGB_565 on low RAM
Release APK
Build failed entirely
3.0 MB, R8 minified
Unit tests
None
30
A crash nobody could see
setExactAndAllowWhileIdle arrived in API 23. The app's minimum is
API 22. Every scheduled alarm would have thrown on Android 5.1 — the oldest
version it claims to support, and the hardest to get hold of to test. Lint found it;
nothing else would have.
The expensive convenience
DocumentFile.listFiles() looks like one call. It queries for the child
IDs, then charges another round trip across a process boundary for every
property of every file. That's where the 1,500 calls came from — and it ran
on a timer.
Enforced, not promised
Plenty of apps say they don't collect anything. This one doesn't declare the
INTERNET permission, so the operating system won't let it open a socket
even if a future contributor tried. The claim is checkable in the manifest.
Questions people ask
What can I do with an old Android tablet?
Make it a digital photo frame. A tablet is already a screen, a power socket and some storage, which is the entire hardware of a photo frame that would otherwise cost real money. The battery being tired doesn't matter, because it lives on a charger.
Can I use a tablet as a digital picture frame?
Yes. You need an app that fills the screen, hides the Android interface, keeps the display awake and starts itself after a power cut. That is what RetroFrame does, and it is free.
Which Android version do I need?
Android 5.1 (Lollipop) or newer. Check Settings → About tablet → Android version. Most photo frame apps require far newer Android and quietly exclude the exact devices worth reusing; RetroFrame goes as low as the folder-picking API allows.
Does it need Wi-Fi, an account, or a subscription?
None of the three. RetroFrame doesn't declare Android's INTERNET
permission at all, so it physically cannot reach a network — your photos never leave
the tablet. There is no account, no subscription and no advertising.
How do I get my photos onto the tablet?
Plug it into your computer with a USB cable and choose File transfer
on the tablet when the notification appears, then copy your pictures into the
Pictures folder. An SD card works too and is easier to change later.
Full walkthrough in the
setup guide.
Will it run on an Amazon Fire tablet?
It should — Fire OS 5 and later are built on Android 5.1+, and sideloading an APK works normally without the Play Store. Fire tablets are among the most common devices sitting unused, so reports from them are especially welcome.
Will leaving it on damage the screen or battery?
Heat is the real risk, not use. Set a sleep schedule, turn the brightness down and give it airflow. On AMOLED tablets a permanently static overlay can burn in, so the schedule matters more there. See choosing a tablet.
Is it really open source?
Yes, GPL-3.0. You can read every line, build it yourself, and change it. If you distribute a modified version you must share your changes under the same licence.
Go get the tablet out of the drawer.
Download RetroFrameVerify what you're installing
9ce964fb0b4e2ec9a2211e4a6dc0924236ae6f033e6d45ad55f5246f53d813e0
SHA-256 of the APK. Run sha256sum on the file you downloaded and
compare — or build it yourself from source and skip trusting anyone.