Jomo takes a technically interesting approach: rather than building its own blocking engine, it's built on top of Apple's own Screen Time/Family Controls system framework, which lets it credibly claim the block persists through force-quitting the app, deleting it, or changing the system clock — because enforcement lives in Apple's operating system, not in Jomo's own process. That's a real architectural choice worth explaining accurately, and it comes with a real limitation: it's iPhone and Mac only, a deliberate trade-off the small team behind it made in exchange for that deeper system-level integration. The company's own messaging leans heavily on trust and transparency, which makes sense for a product whose core pitch depends on convincing users that a screen-time app isn't quietly watching everything else they do on their phone.
What Jomo actually does
Jomo uses Apple's built-in Screen Time API to block selected apps and sites, plus iOS Shortcuts automations as an alternative blocking path for anyone who wants extra flexibility in how a block gets triggered. Because the actual enforcement runs through Apple's own system framework rather than Jomo's own app process, the company's own documentation states the block holds through force-quitting Jomo, deleting it, or changing the system clock — a claim that's architecturally plausible given how Apple's framework is designed, though not something independently verified here beyond taking the vendor's own technical description at face value. Jomo also supports scheduled, recurring blocks in addition to on-demand ones, and its Mac client extends roughly the same Screen-Time-based approach to a laptop or desktop for anyone working across both an iPhone and a Mac.
Where Jomo is honestly the better pick
If you're fully in Apple's ecosystem and want a lock that plausibly survives deleting the blocking app itself — because the enforcement doesn't actually live inside that app — Jomo's system-level approach is a genuinely stronger technical foundation than an app that has to police its own uninstallation using its own, more fragile logic. Its explicit privacy stance (it says it never sees your passwords, messages, or viewed content) is also a fair, verifiable point in its favor, and one that matters to anyone specifically wary of a third-party app having deep visibility into their phone use. That system-level foundation also means Jomo's block genuinely doesn't depend on its own app staying alive in the background the way many competitors' blockers do, which removes an entire category of potential failure that a battery-saving phone might otherwise introduce.
| Feature | Jomo | Mr. Grummel |
|---|---|---|
| Platforms | iPhone and Mac only — no Android | iOS & Android (in development) |
| Core mechanism | Blocks via Apple's own Screen Time API, plus optional Shortcuts automations | Answer a quiz question from the app's curriculum to unlock |
| Self-bypassable by the account holder? | Vendor states the lock persists through force-quit, deletion and clock changes, per Apple's Screen Time framework design — not independently verified here | Not yet released — can't be assessed |
| Physical hardware required? | No | No |
| Price | $5.99/mo, $29.99/yr, or $99.99 lifetime; 3-day free trial | Not yet announced — join the waiting list |
The one mechanical difference that actually matters
The real difference here isn't the friction type — it's the platform bet. Jomo leans entirely on Apple's own enforcement machinery, which is a smart, credible way to build a persistent lock, but it locks the product out of Android entirely as a direct consequence, a trade-off the team behind Jomo appears to have made deliberately rather than by oversight. Mr. Grummel doesn't have access to that same system-level machinery on either platform, so it relies on the quiz question itself to do the work — a lighter mechanism, but one that works the same way regardless of which phone you carry, without needing to sacrifice half of the phone market to get there. It's worth adding that this isn't really a criticism of Jomo's engineering choices, which are arguably the smarter bet for anyone entirely inside Apple's ecosystem — it's simply a description of a trade-off that happens to rule out roughly half the phone market.
Who should pick which
If you're an iPhone or Mac user who wants a lock built directly on Apple's own persistence guarantees, Jomo's architecture is doing something Mr. Grummel can't currently match on either platform, and it's a genuinely well-engineered use of tools Apple itself provides. If you're on Android, or you want one app that behaves the same way regardless of which phone you're using — including a partner's, a family's, or a work phone that isn't an iPhone at all — that cross-platform consistency is where Mr. Grummel's approach holds up instead. It's also worth considering that a household split between iPhone and Android users can't standardise on Jomo at all, which is exactly the kind of situation a cross-platform tool like Mr. Grummel is specifically trying to cover instead. That said, anyone genuinely torn between the two is probably better served by being honest about which phone they actually own, since the platform question settles most of the rest of the decision on its own.