The short table
Eight rows, pulled from the full matrix on the comparison page and split across the two apps, because they are two halves of one arrangement rather than two rivals. One cell in the AnkiDroid column is a dash rather than a tick or a cross, and the reason is under the table.
Swipe the table sideways to see every competitor
| Feature | Popcue | One Sec | Hopopop | Opal | ScreenZen | FocuzPass | App Pause | Study Lock | AnkiBlock | Tok Blok | LLLock |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Wraps any app you choose | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Puts a question in front of you before you get in | Yes | Partly | Yes | No | Partly | Yes | No | Yes | Yes | Yes | Yes |
| The question comes from material you already keep | Yes | No | No | No | No | No | No | No | Yes | No | No |
| Works from a live tool, not an exported file | Yes | No | No | No | No | No | No | No | Yes | No | No |
| Interrupts at a per-launch ratio, not a daily quota | Yes | No | No | No | No | No | No | Yes | No | No | Yes |
| No skip control on either step | Yes | Partly | Partly | Partly | Partly | No | Yes | Partly | Partly | Yes | Yes |
| Spaced repetition scheduling | Yes | No | No | No | No | No | No | No | Partly | No | Partly |
| Usable free, with no subscription | Yes | Partly | Partly | Partly | Yes | Yes | Yes | Partly | Yes | Partly | Partly |
| Android | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | No | Yes |
| iOS | No | Yes | Yes | Yes | Yes | No | No | Yes | No | Yes | Yes |
| Blocks websites | No | Yes | No | No | No | No | Yes | No | No | No | No |
What “partly” means, and where each claim was checked
- One Sec: Puts a question in front of you before you get in
- One Sec documents a Lengo vocabulary integration and a conversational reflection prompt, so it can add a study step. Neither asks you something drawn from your own notes.
- ScreenZen: Puts a question in front of you before you get in
- ScreenZen lets you write a custom prompt to answer before unlocking. That is a prompt gate rather than graded recall: there is no answer to get right.
- One Sec: No skip control on either step
- One Sec’s interventions are designed to be stepped through, but a reflection prompt is an activity rather than graded recall. There is no answer to get right and then rate.
- Hopopop: No skip control on either step
- Hopopop is the closest thing to Popcue in this category, and its questions are built in: mental arithmetic at three difficulty levels, general knowledge across ten-plus categories, and a geography map quiz. Its own support page documents the skip: you can skip after three attempts, you earn no XP for it, and the app stays blocked for the rest of that session. The gate is real and it is not graded recall of anything you wrote.
- Opal: No skip control on either step
- Opal has a Hard Mode its own site describes as "no way out, you can’t turn Opal off". That is stricter than Popcue, and it is worth knowing that is the trade you are making.
- ScreenZen: No skip control on either step
- ScreenZen documents a limited number of unlocks, so the gate holds. The prompt is self-graded, so nothing records whether you got it right.
- Study Lock: No skip control on either step
- Study Lock earns screen time back by answering correctly, so the gate is real. But it is a time debt, not a block. Get it wrong and you owe more time, which is a different mechanic from Popcue’s.
- AnkiBlock: No skip control on either step
- AnkiBlock offers a 60-second temporary unlock, up to three times a day. This is the clearest no-skip difference in the table, and AnkiBlock’s own listing documents the bypass plainly.
- AnkiBlock: Spaced repetition scheduling
- AnkiBlock schedules nothing itself. It delegates to AnkiDroid, so it inherits SM-2 from the deck you already keep.
- LLLock: Spaced repetition scheduling
- LLLock repeats words before you would forget them. It does not document which algorithm it uses.
- One Sec: Usable free, with no subscription
- One Sec blocks one app free and sells the rest. Its own pricing page returned a 404 at the date above, so no figure is quoted here.
- Hopopop: Usable free, with no subscription
- Hopopop documents a seven-day trial with no card needed, and no permanent free tier anywhere on its site. Its pricing is quoted in euros, and the figures differ between its own support page and its own store listing, so none are reproduced here.
- Opal: Usable free, with no subscription
- Opal allows one rule free. The rest is $99.99/year, $239/year, or $399 lifetime.
- Study Lock: Usable free, with no subscription
- Study Lock is free up to an allowance, then $34.99/year or $5.99/month.
- Tok Blok: Usable free, with no subscription
- Tok Blok has a free tier and a seven-day trial. The App Store lists monthly and yearly subscriptions plus coin packs, and its own blog quotes a different annual price than the store does, so neither figure is repeated here.
- LLLock: Usable free, with no subscription
- LLLock has in-app purchases. Its exact price was not verifiable at the date above.
Every capability claim above was checked on 2026-10-01 against the product’s own public listing: One Sec, Hopopop, Opal, ScreenZen, FocuzPass, App Pause, Study Lock, AnkiBlock, Tok Blok, LLLock. We are not affiliated with any of them. If something here is out of date, tell us and we will correct it and change the date.
Where Anki or AnkiBlock is better
The honest answer to the question in the title is: on price, on evidence, and on everything to do with not needing a habit you do not have yet. This section is the longest on the site for that reason.
- They are free, and Popcue is not entirely. AnkiDroid and AnkiBlock cost nothing at all, with no Pro tier and no decision to make. Popcue is free forever from your own tools, but Pro exists at ₹149 a month or ₹999 a year. If your budget is zero, that is the end of the comparison.
- 10M+ downloads, around 165,000 reviews, a 4.7 rating. That is a decade of other people hitting the edge cases first, plus the community that fixes them. Popcue is not on the Play Store, so it has no public install count, no ratings and no reviews whatsoever.
- Open source, on both sides of the arrangement. You can read what AnkiDroid does, and you can read what AnkiBlock does. Popcue is closed source, which is a reasonable thing to want and a reasonable thing to decline.
- SM-2, maintained by the people who have maintained it for years. Popcue uses SM-2 too, and says so, but on the cards it is asked rather than across a whole collection you have curated over years.
- AnkiBlock’s daily card-count goal is a habit loop, and for a lot of people that is the thing that actually keeps them studying. Popcue’s ratio is a friction loop, which is a different bet and not obviously the better one.
- Your collection is already in Anki. Converting a few thousand cards so that Popcue can ask them is real work, and the correct answer for most people is not to do it. If you have never been quizzed at the point of temptation, AnkiBlock is a cheaper place to start.
Where Popcue is better
The same number of points, and the commonest theme is that the Anki arrangement is two apps agreeing about one number.
- One app, one state. AnkiBlock needs AnkiDroid installed and unlocked, and it gates on AnkiDroid’s card count. If the two ever disagree about what you have studied today, the gate is wrong, and the fix is a settings screen in the other app. Popcue has no second opinion to reconcile.
- You do not have to commit to a second study habit. AnkiBlock gates your phone on a daily goal, so on a bad day it converts a good tool into a debt, and the cheapest way to clear the debt is to turn the gate off. Popcue asks you something on five launches in ten and never accumulates a balance.
- The material does not have to be in a study app at all. Notion, AnkiDroid, or an MCP-compatible LLM endpoint you run. If what you are learning is notes you write for other reasons, Popcue asks about those and AnkiBlock cannot.
- No deck to maintain, no import to re-run. Connect a Notion page once and the cards move when your notes move. There is no CSV, no collection, and no sync step to forget.
- A ratio rather than a daily quota. Five out of ten launches by default, randomized within the ratio, per app, with active hours. Popcue does not decide what day you are having a good day, which is what a daily count does whether you want it to or not.
- No bypass, and web as well as Android. AnkiBlock documents a 60-second unlock up to three times a day, and Popcue has no equivalent. Popcue also runs on the web, so the same cards can be asked on a laptop. AnkiDroid is Android only.
And what about Mochi?
Mochi could not be verified, so this page does not rely on it. We could not read Mochi’s own listing on 30 September 2026, so there is no claim about what it does, what it costs, which platforms it runs on, or how it schedules. Nothing in the table or the text above is a comparison against Mochi.
If you are choosing between Popcue and Mochi, we are the wrong source for it. Read Mochi’s own listing and pricing directly.
Who should pick which
- Keep AnkiDroid and add AnkiBlock if
- You already keep a collection, you are on Android, and the gate has never felt like a debt. It is free, it is proven, and this page is not going to talk you out of it. Adding Popcue on top would be a third app for the same job.
- Pick Popcue if
- You are not going to maintain a flashcard collection, and the material you want to be quizzed on is notes you already write somewhere. You would rather be asked about them five times in ten than be told to hit a daily number before your phone unlocks.
- Use both, and notice what that costs
- Popcue reads AnkiDroid decks directly, so if you have both, Popcue can be the interrupt and AnkiDroid the source. That is a supported arrangement and not a workaround, but it is still two apps, and the honest question is whether you need both.
Where this came from
Three sources, all read on 30 September 2026: AnkiDroid’s Google Play listing (10M+ downloads, around 165,000 reviews, 4.7, free, open source, SM-2), apps.ankiweb.net, and AnkiBlock’s Google Play listing (free, open source, a few hundred downloads, the “unlock distracting apps by finishing your AnkiDroid flashcards” description, the daily card-count goal, and the 60-second unlock up to three times a day). Mochi is not cited because it could not be read. Popcue is not affiliated with any of them, and if you own one and something here is wrong, tell us and we will change it and move the date.
Three questions
Do I need Popcue if I already use Anki?
Probably not, and we would rather say so than sell against it. AnkiDroid is free, open source, community-developed, has more than 10 million Google Play downloads and about 165,000 reviews at a 4.7 rating, and it schedules with SM-2. AnkiBlock adds the app gate on top of it, also free and also open source.
If that habit already exists, it is free and nothing on this site should talk you out of it. Popcue’s case is for people who do not want to run a second study app at all.
What does AnkiBlock actually do?
AnkiBlock is a free, open-source Android app with a few hundred downloads whose own Google Play listing says you unlock distracting apps by finishing your AnkiDroid flashcards. It sets a daily card-count goal, and it offers a 60-second temporary unlock, up to three times a day.
It does not schedule anything itself: it delegates to AnkiDroid, so it inherits SM-2 from the deck you already keep.
Is AnkiDroid free?
Yes, and it is also open source and community-developed, which is the reason it has survived where other flashcard apps have not. Its Google Play listing shows more than 10 million downloads, about 165,000 reviews and a 4.7 rating. Anki and AnkiWeb, where your collection and decks are synchronised, are free to use as well.
Popcue can also read your AnkiDroid decks directly, so the two are not mutually exclusive.