Pinned Tab Sync by Joofthan

This add-on synchronizes pinned tabs across multiple devices. It also keeps pinned tabs in sync across all windows. Additionally, this add-on resolves the issue of pinned tabs repeatedly disappearing, as it handles the storage of pinned tabs.

Note:
- To sync across multiple devices, you must be signed in to the same Firefox Sync account on all devices.
- The add-on saves the URLs of the pinned tabs to Firefox's sync storage. This means that the URLs of the pinned tabs are transferred to Mozilla if you are signed in to Firefox with your Mozilla account.