We're implementing a "single session" solution in our mobile app ecosystem in order to avoid the case of users logging in with the same account and running more than one session on multiple devices. Starting a new session i.e. signing in with the same account on a new device will result with a message (for example, a full-screen modal dialog) on the other device that will force the user to log out / terminate the previous session.
Any examples of similar UX flows, or ideas for what kind of language should this message contain in order to keep it clear and friendly?
Thanks! G