[Solved] send text from one android device to another through wifi [duplicate]

Adding Network Service Discovery (NSD) to your app allows your users
to identify other devices on the local network that support the
services your app requests. This is useful for a variety of
peer-to-peer applications such as file sharing or multi-player gaming.
Android’s NSD APIs simplify the effort required for you to implement
such features.

https://developer.android.com/training/connect-devices-wirelessly/nsd.html