Not sure about mobile, i used it on laptop. You'll have to go thru Tor network. Its basically a place to buy non kyc. Look up BTC Sessions, he has an excellent tutorial on it.

Yes, there is an android app, but not on the play store. You have to install the apk from the github page. But Robosats works fine in the Tor browser as well, so no need to get the app. I have used it regularly for about a year without issues. Here is the link in case you want to tlry the app:

GitHub

GitHub - RoboSats/robosats: A simple and private bitcoin exchange

A simple and private bitcoin exchange. Contribute to RoboSats/robosats development by creating an account on GitHub.