Substack's model is subscription newsletters — you don't go looking for the next piece, it arrives in an inbox or an app feed on the writer's schedule, not yours. That inversion changes the psychology from most of this list: the pull isn't "is there anything new," it's "how many unread ones have piled up," which turns reading into something closer to email triage than casual browsing, and an unread badge that only ever climbs.
What actually makes Substack hard to close
Subscribing to several newsletters means new issues arrive on their own schedules regardless of whether you have time to read them, so the backlog grows independent of any decision you're making — it isn't a feed you chose to scroll, it's a queue you're falling behind on, which produces guilt rather than curiosity as the main driver. "Notes," Substack's short-post social feed layered on top of the newsletter product, adds a scrollable, comment-and-repost habit similar to X or Threads directly inside what used to be a straightforward reading app, blurring a subscription-based habit with a feed-based one. Comment sections under a piece you've read can turn into their own extended discussion to follow, especially on a newsletter with an engaged community, adding a Reddit-like thread-checking habit on top of the reading itself.
The built-in iPhone route, and where it gives way
An iOS Screen Time App Limit on Substack behaves like it does on any app: a warning, a lock screen, one "Ignore Limit for Today" button that clears it in a tap, needing only a Screen Time passcode you set and know yourself. "I need to clear my backlog" is a specific, guilt-driven override reason that other apps on this list can't quite manufacture — the unread count feels like an obligation, not a distraction, which makes tapping through the limit feel almost responsible.
The built-in Android route, and where it gives way
Digital Wellbeing's App Timer greys out Substack's icon at your limit and offers more time the moment you tap it, adjustable or removable from Settings whenever you like. Same gap as iPhone: the timer can't distinguish clearing a genuine backlog from scrolling Notes, which is a very different activity wearing the same app icon.
What changes when the toll is three questions
Mr. Grummel's toll costs the same few minutes of real thought whether you're opening the app to read one specific newsletter or to make a dent in a backlog that's grown past the point of ever being cleared. That a few minutes are enough to ask which one is actually happening — because "catching up" on Substack often turns into a Notes session that has nothing to do with the backlog at all, and a toll placed before the app opens catches that switch before it happens rather than twenty minutes into it.
A realistic day
Right now: opening the app to read one newsletter you're genuinely behind on turns into a scroll through Notes, and the backlog is exactly as long when you close the app as it was when you opened it, just with twenty minutes gone in between. With the toll in place: opening Substack runs into three questions first. A newsletter you're actually going to read still gets read. What's interrupted is the guilt-driven open that turns into browsing Notes instead of the backlog it was supposedly meant to address, which now costs a few minutes of real thinking before the app opens, not after the scroll's already replaced the reason you were there.