Power Planner is mostly a free app, however for $2.99 USD, you can unlock a few additional features.
The purchase is a one-time, lifetime purchase, and it also syncs across your account, so if you purchase on Android, you'll also unlock premium on Windows and iOS!
The free version is limited to...
- 1 semester
- 5 grades per class
- 1 repeating bulk entry of a task/event
- Cannot pin classes as secondary tiles (Windows app only)
- 1 photo attachment per item (photo attachments not supported on iOS yet)