They also publish a fully functional C library that makes building fully (!) featured 3rd party clients easy. They support everything - from Linux, Windows all the way to Tizen. You compile it into your app and it "just works" with all the features of the main client.

As a result, you have a large set of very good clients for pretty much all platforms.

Imagine if the FLOSS darlings like Signal would make something as amazing as this - a library any plaform (from RPi, watches, etc.) to implement the best possible secure client that fits the user.