What's better than free in-app 3G calling? Cross-platform 3G calling. Delivering on old promises, Viber is offering an Android version of their free, no-registration VoIP app to beta applicants this week. The Android beta keeps everything from the iPhone original, plus a few bonus features -- including the ability to respond to text messages without opening the app, natively viewable in-app call logs from non-Viber calls, and the ability to set Viber as the default dialer for all applications. All this, and cross platform support? Sign us up! Oh, wait -- no registration required. It just works. The current version of the app has been tested on devices from Samsung, HTC, Sony Ericsson, and more, but the full release is waiting on beta testers to weigh in on the fragmentation front. See a video of Android and iOS playing nice after the break.