Watchmarker for Youtube for Chrome
More About Watchmarker for Youtube
***Does this work with the old Youtube theme?*** I am afraid that only the new theme is supported. If you do not know which theme you are currently using then it is very likely the new one.
***How can the persistence of the database be ensured?*** There is an export and import feature, which makes it easy to create a backup of the history. This backup can easily be archived such that you can ensure that you never lose your history.
***How can I make sure that the database is complete?*** The automatic synchronization only considers the recent activity. You are thus encouraged to manually initiate a complete synchronization in the settings, which incorporates as much of your history as possible.
***Something is broken, I demand a fix!*** Please be considerate when leaving a review, this is a free extension that I invest my spare time in. If there is something that does not work then please file an issue on Github where it is easier for me to track.