At Embrace, we define a session as each unique device interaction in which a Customer app opens to the foreground. When the app is backgrounded (the app crashes or the user implements a manual end to the session) that marks the end of that session.
There is no minimum or maximum time limit for a session. Sessions within five minutes of one another are stitched together to represent a single user experience (a stitched session).
If a user clicks a link in the app and this opens the web browser (also known as embedded browser), and then exits the browser back into the app, this is still a single session.