The app your rear-window sign should have shipped with.
Bought a cheap LED sign online, and the app that came with it barely works? That's why RearSign exists. It connects on its own, tells you what your sign is actually showing, and doesn't make you fight it every time you get in the car. Send text, emoji, and icons to the drivers behind you, right from your iPhone.
Always know what's on your sign
See whether the sign is connected and exactly what it's displaying, dot for dot. RearSign reconnects automatically when your car starts, even with the app closed, and every message is confirmed by the sign.
One tap, hands free
Lock Screen and Dynamic Island controls while the sign is connected, a Home Screen widget, a Control Center button, and Siri: “Write on RearSign” or “Clear RearSign.”
Messages that look great
Full-height lettering, full-color emoji, icons like arrows and hearts, and a live dot-matrix preview. Ready-made messages for the road: THX, OOPS, YOU GO, NO RUSH, STUDENT DRIVER, and more.
See it on a real sign.
Twenty-seven seconds of RearSign driving a 96×16 sign in a rear window: typing a message, sending saved messages, and scrolling text with emoji. No audio.
Starts the way you want.
Choose what the sign shows when your car starts: stay blank, keep your last message, or show a favorite. It's saved on the sign itself, so it works even without your phone.
A closer look.
RearSign Pro
A one-time $0.99 purchase adds effects (scroll in any direction, blink, breathe, snowflakes, typewriter, rainbow color styles), auto-disappearing messages with a hide animation, and startup control.
Compatibility
RearSign works with Bluetooth LED matrix panels that appear as “LED_BLE” (tested with 96×16 rear window signs). Requires an iPhone running iOS 18 or later. No accounts, no ads, no data collection. Check your local laws on illuminated displays in vehicles before use.
