I love FluffyChat. Been using it for a month now and it's significantly faster than Element/SchildiChat on Android. It has the basic chat features I would expect from a Matrix application. Only feature I don't think it has crosssigning at the moment. (In which you're signing your friends master-key, which they use to sign their new devices, so you don't have to have a cryptoparty anytime a friend adds a new device)