You've already tried the reminder apps. They get dismissed. Posture Sensei doesn't ask you to sit up. It makes slouching cost you something you care about.
Two anime guardians sit on your real shoulders and fight skeletons. Your posture powers them. Slouch and they start dying. Their attacks weaken. Their shield drops. HP drains. When it hits zero, your screen locks at the OS level — and the only way back is holding perfect posture for 20 seconds straight.
After a few of these, your body starts catching itself before the guardians ever take damage. That's the point.
HOW IT WORKS
Open the app before a long sit. Coding block, study session, work sprint, gaming marathon — anything where you tend to fold forward.
Your camera tracks your shoulders, spine, and head 30 times a second using Apple Vision. Two guardians anchor to your detected shoulders and fight skeletons that swarm from every edge of the screen.
Sit straight and your guardians fight at full power. Shield up. HP regenerating. Enemies pushed back. The session feels calm.
Slouch and everything turns. Damage drops. Shield flickers. Enemy hits land. HP drains fast.
Lose the fight and your screen disappears. Fullscreen overlay at the OS level. Can't cmd+tab. Can't close it. Hold perfect posture for a 20-second countdown to unlock. Drop during the countdown and it resets.
WHY IT WORKS WHEN OTHER APPS DON'T
You can't swipe this away. A notification gets dismissed in half a second. A dying guardian and a locked screen don't.
The feedback is instant. Not "check your posture" thirty minutes later. The fight reacts the moment your shoulder drops, while correction is still easy.
It's literally your body up there. The guardians pin to your actual shoulders via the camera. Shift, lean, slouch — they move with you. You're not rooting for a character on a screen. You're watching yourself get hit in real time.
Your brain rewires itself. After a few screen locks, you start self-correcting automatically. The habit forms because the loop is real, not because an app told you to sit up.
PRIVACY
Apple Vision processes every camera frame locally on your Mac. Frames are never saved, never uploaded, never shared with us or anyone else. No accounts, no servers, no posture logs anywhere. You can verify with Little Snitch.
WORKS WITH YOUR SETUP
Runs on macOS 14 and up. Apple Silicon recommended. Works with the built-in FaceTime camera or any USB webcam macOS recognizes. Single monitor, dual display, 49-inch ultrawide — pick which screen the lock covers.
Posture tracking runs on the Neural Engine, not the main CPU. About 2% CPU usage. Battery impact stays negligible on M-series Macs.
Optional AirPods head tracking adds extra signal when you're wearing them.
If a video call grabs your camera exclusively, Posture Sensei pauses automatically and picks back up when the call ends. Menu-bar pause for breaks, coffee runs, or anyone walking into the room.
Adjust what counts as good posture: strict, normal, or chill. Or calibrate to your own baseline by sitting the way you want to sit for ten seconds during setup.
ONE-TIME PURCHASE
No subscription. No tiers. No accounts. Buy it once on the App Store and own every future update forever.
WHO IT'S FOR
Software engineers, designers, writers, and anyone whose job lives in a chair. Students working through long sessions. Gamers who fold into the desk after hour two. People who've already bought the corrector, the standing desk, and the $40 brace in the drawer.
If you've tried everything else and your spine is still asking questions, this is the one that doesn't let you ignore it.
Sit up or your screen goes dark.