Weasel is a messenger application that allows you to exchange conversations with the other person on one screen.
Message content or friend information is not stored on the server, but on the device.
You don't use a server, so you have to add your contacts yourself.

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After installation, you must go to'Settings> Battery Optimization> All Apps> Select Weasel> Do Not Optimize' to receive notifications even after the application ends.
When deleting the application or deleting data, all data is erased.