Tiny Flashlight + LED Really, if the smartphone is the swiss army knife of today, you need to have a flashlight. Comes in handy when venturing into dark scary places or if you need to reset a circuit breaker.
Sky Map Shows off the coolness of your Android device, makes you look smart, and helps you find the Big Dipper and North Star.
InstEbooks Unlimited Gives you the power to publish photo ebooks right from your Android. Let's you add captions using speech to text and automatically generates maps of where your photos were taken. Publishes in standard ePub format so you can send to anyone on any device and they can view it.
Angry Birds If you need one go-to game that appeals to everyone from toddler to senior citizen this is the one. Must have if you need to placate someone for 10 minutes. Sometimes the hype is deserved.
Dropbox Wonderful service for accessing your files from any device. Need to see that spreadsheet on your laptop, tablet, and smartphone? – voila.