The Amazon Kindle is a great ereader, but it's not particularly feature-rich. Reabble is a simple little RSS reader optimised to work inside the Kindle's experimental browser to make reading articles less of a chore. Reabble hooks into the RSS reader Inoreader, so you'll do your non-Kindle management there. Otherwise, it works pretty much like any other RSS reader on the market, just on your Kindle. Because of the way the Kindle works, this isn't an app or anything, it's just a simple a website that you'll point the Kindle's browser to. Unlike other RSS readers, it's optimised to actually look good on the Kindle.
The one caveat is a slightly bizarre pricing model of $0.90 ($1.20)/month if you want to read more than 15 articles a day. That seems easy to get around by only tapping on the articles you actually want to read, but it's still worth noting, especially if you have a lot of feeds. There are plenty of other simple ways to send articles to your Kindle for reading, but an RSS reader certainly makes things easy to manage.