In Fast Budget there are various ways to see how much you have earned or spent in each category or subcategory.
The summary page is divided in two tabs.
In the right tab, you can see a list your categories/subcategoeries with the value spent in each one.
Categories chart page
Using the pie chart, you can have a visual representation of the value spent/earned by category.
If you press on a slice, you can see the related subcategories or the transactions in the selected period.
In the "Transactions" page, press on the magnifying glass in the top menu to filter your transactions by one or more categories.
There are also many other search options.