Apple has completely discontinued support for "legacy" .safariextz extensions in macOS Catalina. (It was deprecated but still functional in Mojave and High Sierra.) I've chosen to stop supporting this extension. The final version (1.7) is still available here. Recent versions of Safari have some similar features (for example, a list of recently closed tabs in the History menu).
Recent Tab List for Safari
A Safari extension that keeps track of recently closed tabs and allows you to reopen them quickly. Will also (optionally) display currently open tabs. With a live text filter for easy searching.
Right now it has 5 settings:
- Number of recent tabs in the list
- Open tabs in foreground or background
- Show/hide currently open tabs
- Show open tabs list before recent tabs
- Disable recent tab tracking when private browsing is on
- The Safari Extension API doesn't reveal private browsing status by window (just on or off for the whole browser). If private browsing tracking is off, the extension will also skip tabs in your non-private windows