SonderAssist

Locks the screen when your phone is taken from your hand.

Why this exists Android already has Theft Detection Lock, and it is good. It watches the motion sensors for a phone being snatched and locks the screen. But it waits for the getaway — the snatch followed by running, biking or driving.

That leaves a gap, and it is the ordinary case. Someone takes your phone and walks off. Someone takes it as the train doors close. Neither produces a getaway the model recognises, so the screen stays unlocked with everything on it.

SonderAssist fires on the grab itself.

It is not a replacement for Theft Detection Lock. Leave that on. This covers a case it does not.

What it does Locks instantly. A sharp pull toward the top of the phone, in the phone's own frame, with the phone actually moving — then a confirmation window that rejects a drop and rejects being put down. Device Admin force-lock, so the screen comes back needing your PIN.

Makes a noise. On the alarm channel at full volume, so it is heard through silent mode. It waits a few seconds first, which is what lets you cancel a false alarm before it wakes a room.

Says something on the lock screen. Your message, over your picture, readable by whoever is holding it.

J.A.R.V.I.S mode. A different alert screen — your message on a dark field, with turning rings under each finger — and its own sound, played once. It is cleared by a three-part gesture: two fingers tapped, two fingers up, one finger across.

Closes the power menu. While the phone is locked by a theft, both routes to it stop working, so it cannot be switched off with two taps. Needs Shizuku. Off by default.

Holds the screen. If something opens over the alert — the assistant, on a long press of the power button — the phone goes dark and silent instead, and the alert comes back when the screen does. Swiping it away just puts it back.

Sends its position. If it is not unlocked in time, the phone texts a number you choose and drops a live location pin in a Telegram group through your own bot, moving in place until you stop it. Every message carries the battery level and whether it is charging.

What it does not do It does not get your phone back. It protects what is on the screen, and it tells you where the phone is. Recovering it is not something an app does. It cannot stop the phone being switched off. Holding the power button for about ten seconds cuts power below the operating system. No software can block that — not this, not Samsung's, not a custom ROM. Everything here is designed around getting a position out before that happens. It does not help if the phone was already locked, because there is nothing to protect. It does not yet cover a phone taken from a table, a pocket or a bag. Those are different signatures and each needs its own work.

Accuracy, honestly A platform feature shipping to a billion phones has to tune for almost no false alarms, because every wrong lock is a support burden. This does not. A wrong lock here costs one fingerprint touch, so it fires on evidence that would be far too thin for Google — and that asymmetry is the only reason a small app can catch what theirs misses.

Expect it to lock sometimes when you did not mean it to. That is the trade, made on purpose. If it is not the trade you want, this app is not for you.

The thresholds are reasoned from physics rather than measured from recordings. Sensitivity moves all of them together and shows you the real figures, not a word.

Licence GPL-3.0-only.