Categories organise your transactions; every transaction has one. They group spending and income in reports and budgets.
Expense and income
Each category is set to expense or income by default. That type is picked when you select the category in a transaction, but you can switch it for that transaction. For example, a Work category can hold work income and work expenses.
Subcategories
Each category can have subcategories, created on the category's page. Totals get more detailed when transactions use subcategories. A main category can also become a subcategory: edit it and choose Convert into subcategory.
Merge categories
When editing a category, Merge category moves all of its transactions to another category.
Balance correction
The Balance correction category is special: transfers and balance fixes use it, and it doesn't count as income or expense. See Balance correction.
Create and edit categories
In Categories (on a phone, under More; on a computer, under Edit data) you can create categories, change their order and edit existing ones.
Tags
Tags group transactions from different categories under one theme, for example "Trip to Benguela" (hotel, restaurants, fuel). A transaction can have several. Pick them on the transaction page, in the row below goals; the tag button creates a new one. In Tags (on a phone, under More; on a computer, under Edit data) you see each tag's total, tap to see its transactions and use the pencil to rename, change the colour, archive or delete it. In search, the filters have a row of tags.