MasaApps360
English
Don't Touch

How to use a "don't touch my phone" app on iPhone

Open Don't Touch, set a 4-digit PIN, tap ARM and put the phone down. Once the countdown ends, any pickup, tilt or slide starts a siren that only your PIN can stop. I ran this on my own desk for a week before writing it up. How much movement counts as a touch is up to you, through the Motion Sensitivity slider.

3 min read · Updated 2026-09-07

Download on the App Store

When a "don't touch" alarm helps

You step away for a minute: the counter, the bathroom, the printer. Your phone stays on the table. A phone that starts screaming the moment it is lifted is a phone most people put straight back, and that minute suddenly feels less risky.

It also works well against nosy friends and siblings checking a phone that isn't theirs.

How to set it up and arm it

  1. Install Don't Touch and open it. A short walkthrough explains the alarms and asks you to allow notifications, so a banner titled "Alarm triggered" tells you why it went off.
  2. Set a 4-digit PIN, then Confirm your PIN.
  3. Place the phone where it will stay, screen up, and tap the big ARM button. The first time, iOS also asks to allow motion access — without it the app has nothing to feel movement with.
  4. Let go during the countdown: the screen reads Arming — put your phone down now.
  5. When it shows Armed. Don't touch it., walk away with the app still open and the screen on.
  6. To end the session, tap DISARM and type your PIN on the Enter PIN to Disarm pad.

What counts as "touching" the phone?

The app reads the accelerometer 20 times a second and keeps a slowly moving average of how the phone is resting. A touch is a sudden change away from that resting reading. A gentle tilt settles into the average over a couple of seconds; a pickup, a slide or a knock jumps past the limit and fires the siren.

That limit comes straight from the slider: threshold = 0.5 - sensitivity x 0.42, in g (the unit of acceleration where 1 g is gravity). Default sensitivity is 0.5, which lands on a 0.29 g threshold.

Motion Sensitivity and the jolt needed to trigger
Slider valueLabel shown in the appTrigger threshold
0Low — needs a firm bump0.5 g
0.25Low — needs a firm bump0.395 g
0.5Medium0.29 g
0.75High — any small nudge0.185 g
1High — any small nudge0.08 g

So at full sensitivity a change of just 0.08 g is enough, while at zero it takes 0.5 g, a firm bump. Lower numbers in the last column mean a lighter touch sets it off.

Which sensitivity should you pick?

  • Solid desk in a quiet library: Medium or higher, so even a slow pickup trips it.
  • Cafe table where people lean and cups get put down: slide toward Low — needs a firm bump, or you'll get an alarm every time someone sets down a tray.
  • Phone on your own lap or on a train: skip motion entirely; every bump of the carriage would count.

Common mistakes

  • Switching to another app after arming. The guard stops the moment Don't Touch leaves the screen, with no warning.
  • Arming with the phone still in your hand. Raise the arm delay stepper in Settings (it reads "Arm delay: 5s" by default, up to 15 seconds) if 5 seconds is too short.
  • Forgetting the PIN. Nobody can switch the alarm off without it, including you, so pick one you will remember.
  • Low media volume. The siren follows the phone's volume level; test it with Test Alarm (3s) first.

Is the app free?

Yes, and nothing about arming it is held back behind a paywall. All three guards, the siren and the PIN are free. Pro adds an intruder photo, extra sounds, unlimited history and no ads, none of which you need just to scare off a nosy roommate.

Questions and answers

How do I use a don't touch my phone app?
In Don't Touch, set a PIN once, place the phone down, tap ARM and leave the app open. When the countdown finishes, moving the phone starts the siren until the PIN is entered.
Can someone turn off the alarm without my PIN?
Not from inside the app: only the correct PIN takes it from armed or triggered back to disarmed. A wrong code just shows Incorrect PIN — try again.
Why did it go off when nobody touched it?
Probably a knock on the table, not a hand on the phone. Lower Motion Sensitivity: default 0.5 sits at a 0.29 g threshold, and at 0 that rises to 0.5 g.
Does it work with the screen locked?
No. The phone has to stay on the Don't Touch screen for the sensors to be read, so keep the screen on while it is armed.

You might also like

More Don't Touch guides