Recs.
Updated
Element is a client for Matrix, an open federated messaging network.
It can be used in the browser or as a stand-alone software with electron.
Specs
Pros
Pro End-to-End Encryption
In direct messages, Element encrypts every message. Not even the Element developers know what you're saying, or the owners of your home-server.
Cons
Con Still in active yet early development
There is clearly a User Experience issue esp. in web version which the developers are aware of and are working hard to improve. They've got the concept concrete, so UX won't be an issue in no time. Most often used parts are functional, but some are yet not.
The success of riot depends on how fast the development is, or it'll get outdated too quickly as developers of Signal and Telegram have predicted.
Recommendations
Comments
Flagged Pros + Cons
Pro Bridges to other networks
You're not confined within Riot's or even Matrix garden, and you don't have to make users of other networks switch to Matrix.
Out of Date Pros + Cons
Con No message threading
Original intention was to alolow free flow conversation. It is understood that threading is being owrked on so it may be added in future.