Categories
Categories are unique accounts in Pockity which only support expense entries.
They are never owned by the user, and always get credited.
Reimbursements is a specialized category used by the app for reimbursement/income entries. It is the only category that supports both expenses and incomes.
Budgets
Categories support Weekly and Monthly budgets.
When you setup a budget on a category, you can setup both Lock screen and Home screen widgets to get a visual representation of your expenses in such categories.
Budgets are also displayed when creating a new expense, so you always know how much you have left to spend in that specific category.
Rollover Budgets
Rollover budgets are currently not supported in Pockity, however, it is planned for a near-future update following the public release of the app later this year.