If I personally provided you with a link, download from there. If not, download from releases in the repository above. The navigation is pretty much self explanatory. You won't see any chat heads on home screen unless you create a chatroom. To create a chatroom, tap on the search button in the bottom-right of the home screen. Search for your friend. Tap on message. Now chat head for your friend will be visible on the home screen. Make sure you verify your email address after you register.
You can report bugs by opening an issue on the repository. Providing logs and links with screenshots may help me understand the problem in a better way.
You can contact me from the link above or just open an issue on the repository.
To distribute app through Play Store, a payment of $25 is needed to create a developer account, which I don't feel is the necessity right now.
Follow this guide :
Flutter and Dart SDK
You may also need Android Studio or you can also use any editor of your choice. [Android Studio is required for Android SDK and if you plan to use emulator]
Clone my repo to a directory of your choice. Open terminal and
cd
into that directory. In root directory of the project use command flutter run -d
or justflutter run
.