Is there any free single-signon mechanism for Android that gracefully works with non-webapps? Say, something along the lines of...
You launch my app and use
Use Android Account Manager for SSO. Providing references below just for knowledge. You have to dig into account manager. Android developer: https://developer.android.com/training/id-auth Blog with example: https://www.zoftino.com/android-account-manager-&-create-custom-account-type