Heads up to all #Riot users: with the recent attack on @matrix' infrastructure, it's possible that Riot's Google Play version got compromised. This doesn't affect Riot's F-Droid version. Just as Riot started to do now, F-Droid has always signed all its apps on an inaccessible, offline machine. For more information, see https://riot.im/reinstall
To avoid maintenance overhead, however, it's likely to happen that F-Droid users must also change the app in near future. Still, there's no need to act now.
Is it safe? You probably mean secure. Apart from the recent problems with the dev setup, ad always, it depends on your thread.
Nothing is 100% secure. It has its pros and it's cons and if you wanna know if it is better for you personally than other solutions, you will have to compare them in detail