Comment by extraduder_ire

There's also software called Constellation[0] from microcosm that exclusively collects "backlinks", which are items which link to a certain thing. e.g. follow records for an account, reposts/replies/likes on a post. If you click on the Backlinks tab when examining something on pdsls.dev you can see a list of them.

It can be self hosted and is much lighter than running a full appview. The author has a public endpoint for it that's keeping up with the whole network running on a single raspberry pi on his home network.

0: https://www.microcosm.blue/