Then it wouldn't work on Medium-powered sites like hackernoon.com. There is an open, up-for-grabs issue to fix that permission [0] if anyone wants to help us solve this!

In the meantime, there isn't anything crazy you have to do to make it only work on medium.com -- just clone the repo to your machine, change this one line to "https://medium.com/*" [1], and then load the extension in your browser.

[0] https://github.com/thebaer/MMRA/issues/15

[1] https://github.com/thebaer/MMRA/blob/master/manifest.json#L2...