[rsingel]

Google Reader, which y'all claim to love, supported reading any blog, not just Google's owned Blogger.

You could have done the same thing and built a generalized newsletter app.

But instead you built a reader just for Substack, which is clearly built to lock in an open ecosystem, just as medium tried with blogging and Spotify is trying with podcasts.

[internet_jockey]

You can add any RSS feed to the app via reader.substack.com. As long as other newsletter providers support RSS, this should be no problem.