On Android, they first started with TextSecure years ago, then built the voice app, RedPhone.
Signal is a rebranding that began with the first app on the iOS platform, which happened to be the voice app. However, Signal is intended to be a fully "integrated" app, that will include text, voice, photo/video attachments, and hopefully video-chatting eventually, too, to take on Skype.
The Android version of Signal will probably arrive this year, too, and when it does TextSecure and RedPhone should be gone from the Play Store.
Signal is a rebranding that began with the first app on the iOS platform, which happened to be the voice app. However, Signal is intended to be a fully "integrated" app, that will include text, voice, photo/video attachments, and hopefully video-chatting eventually, too, to take on Skype.
The Android version of Signal will probably arrive this year, too, and when it does TextSecure and RedPhone should be gone from the Play Store.