This app is focused on predicting upcoming expenses.
When you create a new account you can specify expenses and incomes. When a new month is created (book month) the app will use your defined expenses to determine if they need to be paid in the next month. If so they will be added.
The app supports different expense occurance types. Weekly expenses (for example grosseries), monthly expenses (like rent), quaterly expenses (once per 3 months) and annual expenses (yearly).
Once a book month has been created for the next month, that month is usable as a account ledger. You can swipe to mark an expense paid and by doing so create a overview of remaining expenses that month that can easily be used to keep track of your account balances.
In the book years view you build a history of expenses for your accounts. This history provides the ledger of the application.
When you update the expenses in the account definition you can update the current month with these expenses from the current month view.

Free version allows maximum 2 accounts to be managed and does not allow shared accounts. The paid version is unlimited and allows account files from shared OneDrive locations (if they are included in your OneDrive).