A free app for Android, by Simon Lam KoonHo.
FreeCall4Free Mobile is an easy-to-use VoIP application that enables users to make and receive calls over the internet using either a Wi-Fi or 3G/4G cellular data network.
It is a softphone solution that offers a simple user interface and crystal-clear sound quality for a smooth Voice over IP experience. It is a phone solution that is perfectly suited for all end users, dial-up service re-sellers or any business who willing to benefit from Freecall communications. Once setup an account, users will no longer be to pay for an expensive phone bill of both domestic and international calls to reach either up to 45 countries. Users have unlimited times and unlimited minutes to make calls in anywhere even while traveling abroad by using Wi-Fi or 3G/4G data plan on any smartphone or tablet.
