(Developed by Sidecar Communications)
Available for devices running Android 2.3.3 and up
Price: Free
Originally reviewed: May

Mobile video sharing applications are all the rage. Apps like Viddy, Socialcam and Color are now the fastest-growing category in both the Google Play marketplace and Apple's App Store according to recent data published by analytics firm Flurry. Based on growth in minutes spent from October 2011 to March 2012, photo and video apps increased by 89 percent in minutes spent per active user, with users spending an average of 231 minutes per month in mobile video apps as the first quarter came to a close.

What's impressive about Sidecar isn't so much what it does, but how it does it: The app features live video and photo sharing features similar to those found in other apps, but it integrates them directly into voice calling capabilities, dramatically expanding the interactive possibilities of voice communications. In addition to its signature See What I See video feature, which allows users to stream real-time footage of whatever is happening around them, Sidecar also supports text messaging, pinpoints callers' respective locations on a map to facilitate meet-ups and allows sharing of address book data.

Sidecar users can call anyone in the world for free, provided both parties have downloaded the app. They also can call anyone in the U.S. and Canada for free over Wi-Fi, and if the call recipient isn't already a Sidecar user, they'll receive a text explaining how to download the app to their device. Viddy, Socialcam and Color may generate more buzz (at least for now), but for sheer usefulness and range of services, Sidecar may have them all beat.