You can try it here
Videittous is a browser based video optimizer. By relying on @ffmpeg/ffmpeg it will take any input video you have in any format understood by FFMpeg and it will produce an mp4 which can be played in almost any device.
In order to be extremely easy to use by non technical people, it is very opinionated on the encoding parameters and process.
This is just another weekend side project I built to learn about: