Android app overview
HILIA started life as an Android app — get it on Google Play. It does hide & reveal on the phone itself, keeps your stego pictures in a private Vault (or scattered into your regular gallery if you prefer), and can lock the whole app behind a passcode — with an optional decoy vault for when you can't simply refuse to unlock your phone.
New here? Start with the step-by-step Using the Android app guide.
App vs web tool
| Android app | Web tool | |
|---|---|---|
| Hide & reveal | ✔ | ✔ |
| Private on-device vault | ✔ | — |
| Decoy vault | ✔ | — |
| Scatter hidden photos into your gallery | ✔ | — |
| App lock (passcode + biometric) | ✔ | — |
| XP leaderboard | ✔ | — |
| Probe & capacity | — | ✔ |
| Covert watermark (embed/extract/detect) | — | ✔ |
| Stamp & reveal | — | ✔ |
| Visible watermark | — | ✔ |
The app is built around on-phone hide & reveal and your private vault. The watermark features (covert, stamp, visible) live only in the web tool — it works fine in a mobile browser if you need them.
Decoy vault
A phone doesn't always get to stay private on your terms — a border check, a workplace policy, or someone simply telling you to unlock it. The decoy vault gives you a second vault with its own passcode. It looks and behaves exactly like your real one, but only shows what you've chosen to put in it; your real vault stays closed behind a different passcode entirely.
It's one more layer, not a guarantee — put something believable in the decoy vault, and never reuse a passcode between it and your real vault. See Passcodes & security for what steganography and a passcode do and don't protect against.
Scatter into gallery
By default, a stego photo you make stays inside Hilia's own Vault. Turn on Scatter in the Hide flow and the finished photo saves into your regular phone gallery instead — mixed in with your other photos, not sitting in an obviously separate album. It's more private, but the trade-off is yours to manage: you have to remember which photo holds your secret, since Hilia can no longer show it to you grouped in the Vault.
Compatibility
Images hidden with a compatible method reveal on either platform, provided the file travels untouched between devices — the same recompression rules apply. When moving stego images between phone and desktop, use a file transfer (drive link, cable, email attachment), never an inline photo share.