PersistentPin by Fabian Klemp

This add-on makes sure that on opening the browser there are the same websites opened and pinned.

The main use case for this if you want to clear your history when closing Firefox but still want to keep your pinned tabs.

To configure the add-on go to the preference tab in the add-on menu (about:addons).

This is a rewrite of the App Tab Initializer add-on.
The rewrite was necessary since this add-on is compatible with the new multiprocess mode of firefox, which improves its speed greatly.

If you have any problems or a suggestion feel free to open an issue on Github.