Here you can find the full changelog of Hotot+ starting from its first release:
Important note about the Firefox version:
It seems that the update to Firefox 49 in some cases can corrupt the database support for Hotot Plus. This prevents the client to access to its database and so it freezes on the startup loading screen. To solve this issue you need to restore your Firefox profile and reinstall the extension. To do that simply go to the about:support address and click on the button on the right called “Restore Firefox”. After the restore you can download again Hotot Plus from Mozilla Addons page and it will work again.
Preliminary note: when you try to login in your account with the new version 9.0 you'll get an error (because of the change of the API key).
To fix this error you need to reset your token by using the specific function under your profile, as you can see from this picture:
http://www.youtube.com/watch?v=xxxxxxxxxxx
now Hotot+ can recognize the most of Youtube video links, whether they are complex as:
http://www.youtube.com/watch?v=xxxxxxxxxxx&feature=g-vrec
or:
http://www.youtube.com/watch?feature=player_embedded&v=xxxxxxxxxxx
or without “http://” and/or “www.” or, finally, whether they come from the shortened URL:
http://www.youtu.be/xxxxxxxxxxx