We have two license types for users within Salesforce:

    A. Time Tracker Users: They can track time for themselves and see their data
    B. Admin/Manager licenses are for people that need to do any of the following:

1. Set up users, configurations, and other related work on the Time Tracker objects
2. Need access to data for multiple people on their team
3. Need reporting access for multiple users
4. Need to Approve time for users on their teams.

Generally, we find with most customers that there is a 1:10 or 1:20 ratio between Managers and Users.