I use trackit: Expense Edition. I think it was only $25 or $30 and can be downloaded OTA if needed.
It's not bad. The graphics are very simple but it does the job well. Has all kinds of types of expenses pre set up plus you can add your own more specific if need be. You can also set up your categories, etc.
They also have an automobile tracker called trackit: Vehicle Edition which I have as well. Same remarks as above, simple, basic and does the job well. Same price too.