Rated 4 out of 5 stars
The add-on will be much more useful if one can use not only German but also English (US/UK) keyboard. It is almost possible except that I cannot find the combination for "э". It is usually "j+e". Another weak point is that if one switches between different windows the text will be lost. Beside these two points the add-on is excellent.This review is for a previous version of the add-on (0.3).
Thank you very much for your feedback. Please update the Add-on to new version (0.4). The new version also works now with other keyboards (including english). Look at the Add-on description for the characters table.