Greasy Fork is available in English.
Save tumblr reblogs and drafts on a timer or manually. Prompts you to save new posts to draft (so they aren't lost). Restore posts automatically (after a browser crash). Options to import, export, or clear saved post data.
This user script will attempt to automatically save your reblogs and drafts which you're editing on the fly so that if your web browser crashes, your or your OS reboots you don't lose any work.
Because of limitations in tumblr it cannot automatically save new original posts but it will prompt you to save to draft after a time period.
You can also import, export your posts to csv, and clear your posts.
