Clearspace, a Y Combinator-backed company founded in 2022, is genuinely the closest competitor to Mr. Grummel's own core idea researched for this whole comparison set: rather than a timer or a hard lock, it makes you pay for access with active effort — either a breathing exercise, or physical exercise like pushups or squats, tracked by your phone's own motion sensor. That's the same basic theory Mr. Grummel is built on, applied to your body instead of your knowledge, and it's a genuinely interesting parallel invention arrived at by a completely different team working on the same underlying problem. The founders have spoken about building Clearspace after noticing that most existing blockers relied on pure willpower or hard locks, with nothing in between that actually asked the user to do something rather than simply wait something out.
What Clearspace actually does
You set restricted apps and time budgets across iOS, Android, and a Chrome extension. When you try to open a restricted app, Clearspace can require a breathing exercise or a set number of physical reps — pushups or squats — verified through your phone's accelerometer and an on-device motion model, before it lets you through, so the app has to actually detect real movement rather than just trusting a self-report. The pushup-based unlock is reported as iOS-only, with no confirmed equivalent currently on Android, which is worth knowing if you're specifically drawn to that particular feature and use an Android phone. Clearspace also offers detailed weekly reports breaking down exactly which apps triggered the most unlock attempts, giving a clearer picture of where your actual pressure points are than a single daily total would.
Where Clearspace is honestly the better pick
The exercise-to-unlock mechanic is a genuinely distinctive, verifiable form of friction — proving you did ten pushups is a real, physical cost that a quiz question simply doesn't ask for, and for anyone who'd rather move than think in that moment, that's a legitimate, different kind of "pay with effort." It's also cross-platform for its core blocking features, covering iOS, Android and the browser in a way not every competitor manages, which matters if your distraction problem spans more than just your phone. The company's Y Combinator backing has also translated into a genuinely polished, frequently updated app, with a level of engineering investment that smaller independent competitors in this comparison set often can't match on their own.
| Feature | Clearspace | Mr. Grummel |
|---|---|---|
| Platforms | iOS, Android, Chrome extension | iOS & Android (in development) |
| Core mechanism | Restricted-app blocking; unlock can require a breathing exercise or physical exercise (pushups/squats) verified via motion sensor | Answer a quiz question from the app's curriculum to unlock |
| Type of effort required to unlock | Physical (reps) or a breathing exercise | Mental (a quiz question) |
| Physical hardware required? | No — uses the phone's built-in motion sensor | No |
| Price | Free tier for core blocking; Premium roughly $44.99–79.99/yr for cross-platform sync and the full exercise-unlock feature | Not yet announced — join the waiting list |
The one mechanical difference that actually matters
Both apps reject the idea that a passive timer is the right tool, and both ask for genuine effort instead of enforcement — that's the real similarity worth naming, and it's rarer than it should be in a category still dominated by countdown timers and toggle switches. Where they diverge is the kind of effort: Clearspace asks your body to do something verifiable (a motion sensor confirms the reps happened), while Mr. Grummel asks your mind to do something verifiable (you either know the answer or you don't, and there's no partial credit for trying). Neither is obviously the better theory — it depends on whether the moment calls for you to move, or to think, and that probably varies from person to person and even from day to day. It's worth adding that Clearspace's physical-effort model has a built-in ceiling that a quiz question doesn't — there's only so many pushups a reasonable unlock can demand before the friction becomes impractical, whereas question difficulty can in principle scale much further.
Who should pick which
If you'd rather the cost be physical — something your body does, checked by a sensor rather than a right answer — Clearspace's pushup-and-squat unlock is a genuinely well-built version of that idea, and it comes with the side benefit of actually being a little more active during your day. If you'd rather the cost be a real question you have to think through, on either iOS or Android, that's the same basic philosophy, applied differently, that Mr. Grummel is built around. It's also entirely reasonable to want both kinds of effort on different apps — physical reps for one habit, a real question for another — though only Clearspace currently offers the exercise option as part of its own single product. It's also worth noting that Clearspace's breathing-exercise option, alongside the pushup one, means Android users aren't left with nothing — they simply don't get the specific physical-rep feature that's currently iOS-exclusive.