A minimalistic budget tracking app with customizability and statistics. Licensed under the BSD license. The vision of this app is to make tracking expenses as simple as possible. I've found other budget apps to sometimes have too many hurdles to jump through in quickly adding entries on the fly. SimpleBudget tries to make it easier by making the "add entry" page the main focus, along with features to speed up adding entries.
Further, many budget apps are limited in the statistics they reveal. Eg, they might only show a full month, which is perhaps less ideal if you started keeping track in the middle of the month and want to know what the last month of spending was. SimpleBudget allows you to choose the date range for statistics. This can also let you see spending over longer ranges of time.
The app is intended to not be prescriptive. It doesn't enforce you spending under a certain amount for each category (the functionality doesn't exist yet, but it will certainly never force you to have such constraints). You can use it to simply keep track of your spending so that you have insight on where your money is going, or you could input income sources (as negative numbers) to try and balance the books.
Stable releases: https://play.google.com/store/apps/details?id=katrinahoffert.simplebudget
The app is a standard Android Studio one, so it should be straightforward to import the project into that and get it running. See the issue tracker for planned features and found bugs. Features and bugs may be reported there.