Crowsflight
Your smartphone makes for a valuable tool when exploring an unfamiliar city, but data chugging maps apps can really hog your battery, potentially leaving you stranded with a dead device. Crowsflight ($Free) uses the GPS capability on your iPhone to help guide you around town. With it, you can cue up a few destinations before you set out, save them in the app, and use the GPS-only compass to make sure you're headed in the right direction. A distance meter gives you realtime feedback on how far you have to go, so you always know when you're getting close.