It supports many social networks such as Facebook and Instagram, and acts as a hub-like fetching server that turns their updates into RSS.
If setting up a server sounds like too much trouble, or you just want to try it out, you might use one of the instances that anyone can access
RSS-Bridge on Docker
I am building it with docker this time as well
Starting it up
$ docker-compose up -dAfter it starts, connect at http://ip:8080
How to use it
There are a great many services, so here is one example with Flickr: the settings for turning photos with the keyword bird on Flickr into RSS

- Open
Show moreon the Flickr Bridge - Enter the keyword you want to follow in Keyword
- Click the Atom button
- A screen with the generated XML appears, so copy that URL and register it in your RSS reader
Things to be aware of
These services can be fetched without logging in, so countermeasures may be taken against this in the future and you cannot necessarily keep using them.
Also, once you have built a server it may be abused as a stepping stone, which is dangerous, so put measures such as access restrictions in place.