just found this from a tumblr post sadly from the github it seems to have been abandoned in 2018 and doesn't run on firefox mobile which is a shame since i prefer mobile, i suppose it will encourage me to read on desktop more XD

you're a life saver.

If you read on AO3 at all, I CANNOT recommend this ENOUGH! So helpful not having to look at certain things anymore! :D

It's so helpful!! I can know which fics I've read as I'm scrolling through tags or author's pages, and which ones I might want to reread (based on the star rating I gave it).

I also am using this on 3 different devices, and the sync is a bit tricky at first, but works great once you've set it up initially.