It is widely accepted that spaced repetition is vital to learning. Many apps (Snapchat, Timehop, etc.) have "Streaks" in them if you log in each day and complete a certain task. Could Absorb add the ability to allow log in streaks, or content streaks? This would be gamification that would encourage users to not simply log in and skim content once, but actually read and re-read content for true internalization of concepts.
This is a widely used function used in many applications. At a real simple level, log-in streaks (eg daily, weekly, monthly as set by Admin), building on time taken, courses completed, courses enrolled etc. Really simple feature that appeals to the masses! Many thanks