Mobile Session Design is all about driving addiction from your players. Pacing content while at the same time giving reasons for your player base to always reach for their phones to play your game.
To understand the best way to design mobile sessions, read these posts:
Step 1: Understand flow and the importance of Easy In, Easy Out.
Step 2: Build player commitments to return to your game through timers & social drivers.
Step 3: Drive strong sessions per day with Implicit reasons to come back.
Step 4: Encourage flexible sessions. Make players feel smart about leaving your game.