Cerbio works by putting a short problem in front of apps you choose. The first decision you make is which apps, and that choice shapes the whole experience. Guard too little and you barely notice it. Guard too much and it starts to feel like a chore. This is how to get it right.
The one rule: guard reflexes, not tools
The apps worth guarding are the ones you open without deciding to. You unlock your phone and your thumb is already on the icon. That reflex is what makes the gate valuable: those openings are frequent, automatic and usually not very important, which makes them the perfect place to insert a ten-second problem.
Apps you open on purpose, to do a specific thing, are a poor fit. Guarding your banking app or your calendar just adds friction to a decision you already made consciously.
A quick test for any app: if you deleted it for a day, would you reach for where it used to be? If yes, guard it.
The usual suspects
For most people the reflex apps are a short list:
- Short-form video. TikTok, Reels, Shorts. The single most reflexive category for most users, and the one where a gate makes the biggest difference.
- Social feeds. Instagram, X, Facebook, Threads, Reddit. Opened dozens of times a day, usually to see "if anything's new."
- YouTube. Especially if you find yourself on the home feed rather than searching for something specific.
- News apps, if you refresh them compulsively rather than reading them at a set time.
- Mobile games that you open in every idle moment.
You don't need to guard all of them. Two or three is the right starting point.
Where to start
Week one: guard your single most reflexive app. Just one. This gives you a feel for the gate without changing much else, and it's usually enough to produce five to ten problems a day on its own. Keep the number of problems per open at one.
Week two: add one or two more. Once the first gate feels normal, add the next most reflexive app or two. This is where the daily rep count climbs into the ten-to-twenty range, which is a meaningful daily workout.
Later: tune the gate, not the list. If you want more challenge, raise the number of problems per open rather than guarding more apps. The free version lets you set up to three problems per gate; Cerbio Pro removes that cap and, more importantly, lets you guard as many apps as you like instead of the limited set in the free version. For most people, guarding multiple apps is the single biggest reason to upgrade.
Apps to leave alone
- Messaging. WhatsApp, iMessage, Signal, Telegram. You open these because someone contacted you. A gate here is just annoying.
- Work tools. Email, Slack, Teams, docs. Same reason.
- Utilities. Maps, camera, weather, payments. Opened with intent, used briefly.
- Anything you use for emergencies or time-sensitive things.
The goal is reps from moments that don't matter, not friction on moments that do.
Two things people get wrong
Guarding to punish themselves. Cerbio isn't a blocker. A wrong answer doesn't lock you out; you just get another problem. If you set it up expecting it to stop you from opening apps, you'll be disappointed. Set it up expecting it to make you think for ten seconds first, and it does exactly that.
Guarding too much on day one. Ten gated apps on the first day means a problem every time you touch your phone, which is a quick route to switching it off. Start small. The habit builds itself from there.
A note on permissions
To know when a guarded app opens, Cerbio needs an Accessibility permission on Android and Screen Time access on iOS. It uses these only to detect the app launch and show the problem. It doesn't read what's on your screen or record what you type, and your scores, streaks and answers stay on your phone. The full detail is on the privacy page.
Pick your two or three. Solve a problem the next time your thumb goes looking. That's the whole setup.