Just about every RSS reader supports discovery if you just put in the address you have in the browser. Personally, though it'd be nice to see the indicator that a site has an RSS feed, I'd rather not clog up my browser with add ons and just throw the address in my RSS reader on the rare occasion I come across a new site I'd like to follow.

For Firefox I use Awesome RSS:

https://addons.mozilla.org/en-US/firefox/addon/awesome-rss/

For Chrome I can't vouch for anything recently but I came across this a while back:

https://chrome.google.com/webstore/detail/get-rss-feed-url/k...

I've been use FeedBro for Firefox for the last couple years and it's great.

https://nodetics.com/feedbro/

Not the gp but Drop Feeds (https://addons.mozilla.org/en-US/firefox/addon/drop-feeds/) is great Firefox RSS reader add-on.

It sits in the sidebar and automatically updates so you can immediately see when a feed updates, then the feed renders in the main panel. This is very useful for news, status pages, and things like live YouTube events.