I have been looking for something like this for a while (I sorely miss the old "Converter" extension!). I have just installed it and the first impression is very positive! Thank you!

[EDIT] first impression confirmed - works really fine for me.

If you are looking for ideas, to further develop this project - In 2015 the developer of the Converter extension ended development and released the code as Open Source - you can find it here https://github.com/Gutza/Converter