A free app for Android, by CAM THỊ HẢO.
Signal is a free, cross-platform messaging app. It’s a text messenger with a twist. Not only can you send text messages to friends, but you can also do video and voice calls with your loved ones.
With this app, you can send text messages and video calls to friends and family even when you are in different countries. You’ll always be able to catch up with what your friends and family are doing.
What’s more is that the calls are always of high quality. Never miss what’s happening in the lives of those you hold dear with this convenient program!