



TonTsu is a Morse code communication app that works where there's no signal — camping, hiking, festivals, emergency preparedness, or just secret messages with friends.
Send with light
- Your message becomes flashlight blinks in Morse code
- One-tap SOS that repeats until you stop it
- Kana and kanji are romanized automatically; Japanese Wabun code supported
- Save frequent messages as presets for one-tap sending
Read light
- The camera decodes blinking lights into text in real time
- A thermal-style view makes light sources pop
- International / Wabun auto-detection, with kana readings for romaji
- 1×/2×/5× zoom catches distant lights
Morse by sound (Pro)
- Generate Morse audio from text and play it back
- Save and share as an audio file (m4a)
- Decode Morse tones around you with the microphone — any pitch works
Learn the code
- Charts for A–Z, Japanese kana, and numbers & symbols
- Tap any character to hear its rhythm
- Three sending speeds: slow, normal, fast
Fully offline
Everything happens on your device. No account, no data collection, no network.
TonTsu Pro (one-time purchase)
- Morse by sound (generate / save / share / mic decoding)
- Color themes (night-vision red & green, and more)
- Preset limit raised from 1 to 20
Note:
- This app is not a substitute for official emergency services.
- Contains flashing-light effects. Take care if you are sensitive to flashing lights.
DETAILS
- Requirements
- iPhone with iOS 17.0 or later
- Price
- Free (in-app purchase: TonTsu Pro, one-time)
- Released
- July 27, 2026
- Updated
- July 28, 2026