On my Android phone, I've been using the Expense IT application. It seems to do everything I need. I'm able to track expenses (with receipt pictures), mileage, and time. The app lets you create different clients and then create different jobs for each of those clients. I've used it for my consulting business to bill customers as well as for expense reporting for various trips that I have to go on. It works great in both situations.

My favorite part is the fact that I can send the expense reports and bills directly from the app....it doesn't force me to go through some website to gen the report...very cool!

Great apps thats worth the look

AJ