Opal has built one of the more developed communities in this category: a daily "focus score," shared co-working sessions, and friend leaderboards that turn staying off your phone into something closer to a group activity than a solo discipline problem. That social layer is a real, deliberate design choice, and for people who respond to peer pressure more than private willpower, it's a genuine strength worth naming plainly. Opal has also grown a genuinely large, active community around the app, which means the leaderboards and co-working sessions actually have other real people in them rather than feeling like a feature nobody uses. Opal has also raised meaningful venture funding, which shows in the polish of its onboarding and its app-store presentation, even if reviewers sometimes flag the price as high relative to a single blocking feature.
What Opal actually does
Opal blocks selected apps and sites for a session you set, then tracks how consistently you stick to it as a daily focus score you can compare against friends. Co-working sessions let you and other Opal users block together at the same time, and a community layer of chats and challenges sits on top of the core blocking feature, so the app functions almost as much as a social space as a blocker. On iOS specifically, Opal can now integrate with the system-level Screen Time passcode so that turning Opal off requires that passcode rather than just a tap through Opal's own settings — but that stronger lock only applies if you've deliberately set it up; the default configuration is softer, and most new users won't have enabled it without being told to. Opal also layers a general "focus score" and streaks on top of individual sessions, so the app is tracking your consistency over weeks, not just whether today's particular block held.
Where Opal is honestly the better pick
If accountability through other people, not just questions you answer alone, is what actually keeps you off your phone, Opal's community and leaderboard features are a real, distinct strength Mr. Grummel doesn't have and isn't trying to build. A daily focus score you can compare against friends creates a kind of social stakes that a private quiz simply can't replicate, and for some people that's the difference between a habit that sticks and one that quietly fades after a week. The co-working sessions in particular are a genuinely well-executed idea — working alongside other Opal users in real time, even virtually, gives the block a social presence a solo app can't manufacture.
| Feature | Opal | Mr. Grummel |
|---|---|---|
| Platforms | iOS, Android, Mac | iOS & Android (in development) |
| Core mechanism | Session blocking plus a social focus score, leaderboards and co-working sessions | Answer a quiz question from the app's curriculum to unlock |
| Self-bypassable by the account holder? | Yes by default (toggle off Screen Time access in system settings); harder if you've separately set an iOS Screen Time passcode | Not yet released — can't be assessed |
| Physical hardware required? | No | No |
| Price | Limited free tier; paid plans from roughly $8.29/mo billed annually up to a lifetime option | Not yet announced — join the waiting list |
The one mechanical difference that actually matters
Opal's default toll is social: a score that drops, a streak that breaks, friends who can see you didn't stay off your phone. Mr. Grummel's toll is private and immediate: a quiz question you either answer correctly or don't, with no audience and no leaderboard involved, and nobody else ever learns whether you got it right or wrong. Neither is strictly stronger — they're targeting different reasons people give in. Opal bets that being seen matters more than anything else, which is a genuinely well-supported theory of behaviour change; Mr. Grummel bets that a small, real cognitive cost in the moment is enough on its own, without needing anyone else to be watching or to ever find out. That distinction plays out differently depending on how public you want your struggle with your phone to be — some people focus better knowing friends can see their score, and others focus worse the moment an audience is involved at all.
Who should pick which
If you already text a friend to keep yourself accountable, or you like the idea of a focus score you can compare against other people and a community of co-workers to check in with, Opal's social layer is doing something Mr. Grummel deliberately doesn't attempt, and it's worth taking seriously if that's genuinely what has worked for you before. If you'd rather the friction lived entirely between you and your phone, with nobody else watching your streak and no leaderboard to keep up with, a quiz question in place of a countdown is the more private version of the same basic idea, without asking you to also manage a social presence around your focus habits. It's also worth remembering that Opal's free tier is genuinely limited to one easy-difficulty session, so trying the social features properly means paying for them, which is a real cost to weigh against Mr. Grummel's still-unannounced pricing.