The simplicity of Signal's messaging experience is a key aspect of its popularity and user appeal. The protocol itself is text-based, making it very easy to send text messages from a variety of devices, including feature phones, laptops, desktops, tablets, and smartphones.

Signal is a new messaging app based on the Open Whisper Systems' protocols, and it is one of the most secure messaging applications out there. You can use Signal to send end-to-end encrypted messages to your friends. It is available across all platforms and can be used to send text messages, photos, videos, and files. You can also use Signal to make secure voice and video calls. 

It is free to use and there are no ads. Also, the best part is that it is open source so you can be sure that no one is listening to your conversations.