I made this iOS app because I noticed that the native Substack app doesn't let you read offline effectively, and given that Substack is generally just text, this app would be straightforward to make.

I think it has two notable features, that being

1. the algorithm to make tradeoffs between storage, content length, and content quality by tracking a bunch of data

2. the app has no backend, tracking, ads, or anything else like that

Presumably you don't have any upcoming flights but if you do, please try it out, especially if you use the Substack app!