Expensify This keeps track of my business expenses, including the ability to take a picture of the receipt so they aren't cluttering up my wallet.

Square Register Sign up for an account with Square at squareup.com and they will send you a dongle you just plug into your phone to swipe credit cards, or you can run them by typing them in as well. Only cost is a per transaction, no contracts!

Quickoffice Pro (Office & PDF) You can edit anything almost as easily as on a desktop.

Google Drive I like being able to keep documents and edit them all in one place, no matter if I'm at a desk or out somewhere. However, editing isn't as easy as Quickoffice, so I use this for minor changes.

ColorNote Notepad Notes I love having a widgit of 'to-do's on my home screen so I won't forget!