Out of the apps I got, I suggest the following:
*Google Voice - allows you to mask your real phone number with the google-number. Also allows you to forward voice messages to the Google "server", where they can transcribe your voice messages to you. Transcription is not 100% perfect, but good for those times when you can't just call your VM service to listen.
*Yelp - no real explanation needed. Good for travelling or just plain-out looking for places to spend your dollar. The 'monocle' is a marvelous idea!! Don't know what I'm talking about? Download Yelp app and use the "monocle" function
*"AndroidLost" or "Wheres My Adroid" - both are tools to find your lost Android phone. Whether it's buried under a sofa cushion or left in the refridgerator. There's Pro's and Con's between these 2, I have both and trying them out to see which one I like more.
AndroidLost allows you to control your phone via website control, AndroidLost.com. You can even send commands from this website to take a picture shot of where the phone is. For example, if you accidently left it at the park or something. You can send the command to take a snap-shot of it's surroundsings (front or back lens) to see where it's at. Or you can GPS locate it. The information is then sent to your email account - usually your GMail account - depending on what you set your email account as.
"Wheres My Android" is another similar app, but works off of SMS messaging. You set a unique message which will set the phone off (ie. ringing and vibrating) or use it to locate it's GPS location. Not quite sure how the GPS functionality works yet.
Either app, you can use to locate a "lost" phone. I think "AndroidLost" is a better app if someone either stole or picked up your lost phone. That way you can track them down.
*GasBuddy - app connects you to the gasbuddy.com database where people enter in gas prices. If you're ever pinching that penny, you can use this to find the nearest and cheapest gas pump. Or you can use it on travels to find the nearest gas pump in general. Works off your location, so data connection is needed.
*Amazon.com AppStore - hey, 1 free app a day, can't beat that. Sure, sometimes the app is worthless or defective, but why not?
*PaperToss - hey, you need something to waste time right? Why not start with this simple app? AngryBirds is overrated, haha!
good luck!