The Retention report allows you to see how often new users are returning to your app. Use the Retention report to gauge user loyalty and see which behaviors drive repeat engagement. You can also compare retention among subsets of users.
Using the Retention Dashboard
The Retention report summarizes the percentage of users who return to your app after a certain amount of time. The table displays the number of users who first used the app on a given day. It then shows the percentage of those users who returned one, two, three, or more days later. The table can also be adjusted to display retention dates Weekly or Monthly.
Like most analytics reports, Retention can be filtered By Dimension and By Profile. Read more about these Filters in the analytics report article.
Data from this report can be exported as a CSV or PDF, sent as a scheduled email, or saved in a custom Dashboard.
Session-Based Retention
Selecting this option will allow you to see the percentage of users who first used your app, and then returned to use it a second time on a later date.
Event-Based Retention 
Selecting this option will allow you to track user retention based on the completion of two Events. The % of Users Returning will be based on the time it took a user to complete both Events. This means the user completed the first event, then left the app, then returned at a later date to complete the second event.
When setting your Events, it’s also possible to include up to four conditions for each Event to further refine your results.
