HY

Sayhi

The messenger that keeps talking when the network stops. Chat, call and play with your people, and switch to radio mesh when there is no signal at all.

HY lives inside the BUBLE app. Free on iPhone and Android.

No serviceMESH
NO
Nooron the mesh · 2 hops away
Zero bars up here. Where are you?SNR 11.5 dB
By the lake. Take the path left at the big tree.✓✓ 508 ms
Found it. On my way 👋SNR 9.0 dB
Hy! I can see you✓✓✓ opened
Message over radio…

HY Mesh

No signal.
Still talking.

Pair a small pocket radio with your phone over Bluetooth. Your messages then travel by radio, from radio to radio and through fixed repeaters on rooftops, with no SIM, no Wi-Fi and no mobile network.

In field testing in the Netherlands
Your phone Bluetooth Pocket radio LoRa radio Repeater on a rooftop LoRa radio Pocket radio Bluetooth Their phone
no network

Works off the grid

Camp, festival, a school trip, a hiking trail or a mobile outage. The radio does not need a mast.

sealed

Encrypted by HY

Each message is sealed on your phone before it goes on air. The radio network only ever carries code it cannot read.

people you know

Keys from HY only

Keys are exchanged through HY, never picked up from the air. A stranger on the radio gets nothing.

text only

Short and sure

Radio is slow, so the mesh carries text. Photos and calls wait for the internet. When you are back online, everything syncs.

One app, two modes

HY for you.
BUBLE for kids.

The same app, the same chats and games. The mode decides who is around the conversation.

Mode 1 HY

For people who chat on their own terms.

  • You choose your contacts
  • Chats, calls, groups and Moments
  • Games to play with friends
  • Mesh mode when the network is gone
Mode 2 BUBLE

For children, with parents and teachers around the bubble.

  • Parents approve every contact
  • Parents can read along, and the child always sees when they do
  • Screen time limits and per-feature switches
  • A safety report straight to trusted adults
One install. Switching modes changes the rules, not the app.

Everything in the app

Hy, and then some.

A full messenger with calling and games built in, in fourteen languages.

Chats and groups

One-on-one and group chats with delivered and read ticks, replies, reactions and polls.

Voice and video calls

Call anyone in your contacts, with the native call screen on iPhone.

Voice messages

Hold, talk, send. For when typing takes too long.

Photos, GIFs, stickers

Share photos and videos, and find the right GIF without leaving the chat.

Moments

Post a moment for your contacts. They react and comment.

Games

Play against friends or the computer, with ratings and leaderboards.

ChessSudokuTetrisPac-ManSnakeAir HockeyMath duelBird

EN · NL · DE · FR · ES · IT · PT · DA · NO · SV · FI · RU · AR · HI

Say hy.

Download BUBLE, open HY, and say hi to your people. Mesh mode comes when the field tests are done.

App Store Google Play