Rated 5 out of 5 stars
This is just one of those add-ons that I cannot live without. But sadly I am doing exactly that right now, as this add-on is not updated to a web-extention format yet, making it incompatible with firefox 57+.
If the author could update it to the new Web-Extention format I would be extatic!
The WebExtension version is available through the beta channel at the moment. See https://github.com/DanielKamkha/PlayPause/issues/41 for more detail.