There is no hard limit on the number of apps that you can have in your Fulcrum plan regardless of what subscription type you are on.

It is recommended to try to group the same data collected into a single app. If you do have a lot of apps, it is recommended to set the status of the apps that are not actively being used to inactive. This will help reduce the amount of space the mobile app takes up on your device, as well as, help reduce sync times.