FriendCaller became one of most recomended VoIP client for Android phone. Currently in beta version, FriendCaller offers very good over-the-internet calls and Instant messaging to anyone around the world. A really cool feature is the ability send a link to someone you want to call without that person having to download and install FriendCaller. The sound quality is very good compared to Skype, which at the time it was still available on Android required the use of a headset for a good listening experience.

Features:

• Works in WiFi zone and over
• 3G/UMTS connection!
• Runs as a background service allowing anyone to reach you anytime
• Instantly FREE VoIP calls to anybody on the Internet using our patented CallMe-Links\
• Easy import of your Android phone contacts

Learn more here.