Last updated: 2026-11-14 · Developer: TanzSoft (Seoul, Republic of Korea)
Hollerwave (“the app”) lets people who are physically near each other chat, send voice messages and photos directly between their phones over Bluetooth and nearby Wi-Fi, without the internet. TanzSoft runs no servers for the app and does not collect, sell or share any personal data.
Summary
No account, no phone number, no sign-in, no advertising, no analytics or tracking SDKs.
The app does not even have the Android internet permission. Nothing is sent to TanzSoft or any server.
Messages, voice messages, photos, your friends list, room codes and your encryption keys are stored only on your phone.
What nearby phones can see
To find friends, your phone broadcasts a short random code over Bluetooth. It contains no name or phone number and changes every day. Only friends you added and people who know your room code can recognise it.
Your name is shown only to friends, to people in your rooms, and — for two minutes — to people nearby when you open the Add friend screen yourself.
The app estimates whether a person is close, medium or far from Bluetooth signal strength. This is not stored and never leaves your phone.
Messages and encryption
Messages to a friend are end-to-end encrypted with standard algorithms (X25519, Ed25519, HPKE with AES-256-GCM). Room messages are encrypted with a key made from the room code: anyone who knows the code can read the room.
Messages may be passed along by up to three phones of your friends or room members to reach someone farther away. Those phones cannot read them and keep only a short-lived copy until it is delivered.
Photos are resized and re-encoded before sending, which removes location and other metadata.
Permissions
Nearby devices (Bluetooth) and nearby Wi-Fi devices: to find and connect to friends' phones.
Location (Android 12 and older only): Android requires it for Bluetooth scanning. The app does not read, store or send your location.
Microphone: only while you hold the talk button to record a voice message.
Notifications: to tell you when a message arrives. A notification is shown while 'Keep listening in background' is on.
Reporting and blocking
You can block anyone on your device; their messages are then neither received nor passed along. Report opens your own e-mail app with the details you choose to send to support@tanzsoft.com. We use reports only to improve safety and do not share them.
Children
The app is not directed at children under 13 and is rated for teens because people can talk to each other. Strangers cannot find or message you unless you share a room code or add them in person.
Deleting your data
Delete a chat, leave a room, or use Settings → Erase everything. Uninstalling the app removes everything stored on your phone. Messages already delivered to other phones stay on those phones unless disappearing messages are turned on.