Great app, very flexible
I am not working for this company, I bought it inspite of what the previous commenter wrote (the guy that wrote the bad review probably had zero patience working with it), and I found that you can actually make your own categories and sub categories, add custom images, move them around etc.
The application does have some issues with the interface (for example, if you want to change an auto payment to a planned bill, you need to delete it and recreate it), but all in all it is great ! , syncs using Dropbox with the iPhone and Ipad.
To create new categories and sub categories do the following:
Once you create a new category using the "+" button, you need to right click on the new item, and choose "open", that allows you to add sub categories.
Asabi about
Bills, v1.6.3