primr vs CRUMB
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
primr
Enhance your focus and productivity with binaural beats and guided meditation. Track your focus improvement over time and unlock new sound packs designed for creativity and productivity.
- Binaural beats for focus
- Guided meditation sessions
- Focus rating after each session
- Track focus improvement over time
- Future sound packs for creativity
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Combining the power of binaural beats and meditation, primr increases your ability to get in the zone and focus on what's important. After each session, you'll get rated on how focused you were and as time goes by you can track how your ability to focus has improved. In future releases, we will be adding binaural beat sound packs that are designed to help improve your creativity and productivity.
CRUMB
Explore and build electronic circuits in an interactive 3D environment. Learn circuit basics, experiment with components, and analyze performance with built-in tools without the risk of damaging real parts.
- Interactive 3D circuit construction
- Wide selection of electronic components
- Study transistors and audio filtering
- Program EEPROMs
- Built-in oscilloscope and analysis views
- Prototype analysis before real-world construction
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CRUMB offers an easy to use and interactive introduction to electronic circuits Fully realised in 3D, you can construct prototype circuits as you would at the workbench without the risk of terminal component failure or the hassle of ordering individual components CRUMB comes with a great selection of components to allow you to jump straight in to creating prototype circuits With the catalogue available, it is possible to study the workings of transistors & audio filtering, all the way to programming an EEPROM to run a basic program For the beginner, it is possible to learn and understand the basics of interactivity, and for the enthusiast it is possible to analyse and perfect prototypes before constructing real world models Using the built in oscilloscope and analysis views, it is possible to see clearly the interaction between components from within the wires themselves Through community feedback and suggestion, there will be many more components and features added. For a full feature list and development schedule please visit the website http://www.crumbsim.com
Screenshots
Verdict
The clearest difference is price: primr at Free against CRUMB's $7.99. primr also leads on rating (5.0 vs 4.4) and review sentiment (83% vs 56%). CRUMB's advantage is update cadence (weekly vs every 2 months) and ratings volume (138 vs 2). On ads, in-app purchases, monetization model and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
primr is free to download; CRUMB costs $7.99 up front. Neither carries in-app purchases, so what you see is what you pay.
primr holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: CRUMB has 138 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 83% of primr's written reviews are positive against 56% of CRUMB's.
primr ships an update every 2 months, CRUMB weekly. The most recent releases landed on October 9, 2026 and October 17, 2026 respectively.
| Parameter | primr | CRUMB |
|---|---|---|
| Price | Free — better | $7.99 |
| Rating | 5.0 (2 ratings) — better | 4.4 (138 ratings) |
| Positive reviews | 83.3% of reviews — better | 55.6% of reviews |
| Number of ratings | 2 | 138 — better |
| Update frequency | Every 2 months | Weekly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Best chart rank | — | #92 — better |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 10.0 — better | 13.0 |
| Further details — not scored | ||
| Size | 39 MB | 496 MB |
| Age rating | 4+ | 4+ |
| Developer | Daily Prompt Ltd | Vital Group Limited |
Customer experience
primr
CRUMB
Bugs and requests
primr
Not enough reviews yet to summarise bugs or requests.
CRUMB
Reported bugs
11 issues- App crashes when using the “corners” option on jumper wires
- Experienced some crashing on Mac
- Component images do not rotate
- Power rails are backwards related to real life breadboards
- Program counters (74HC161) do not reset to 0 on a reset signal
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- 74HC245 enable pin should be labeled active low but it’s not
- EEPROM sometimes corrupts the data saved in the HEX editor
- Many components, most commonly the transistor, lock their image in place even if deleted
- Buttons and switches will react to touching the screen even when not touching the component location
- Rotation is broken on the app version
- UI can be a little flaky at times
Requested features
31 requests- Implement modern components (TI IC, LTC series)
- Add 12 segment display
- Add Arduino and other microcontrollers
- Add a spot to code Arduino/microcontrollers
- Allow custom wire colors
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- Create circuit boards with custom colors
- Add pre-made circuit boards
- Ability to create custom electronic components from circuits
- Improve corner-to-corner wire mode for breadboard/power rail connection
- Add snap rotations and positions
- Add CD4511 component
- Add oscilloscope
- Add signal generator
- Add BJT transistors
- Add op amp
- Add MOSFETs
- Add transformers
- Add relays
- Add AC power supply
- Add music player for amplifier learning
- Add more examples of classic circuits
- Simulation pausing
- Add hotkeys to desktop version
- Add resistance monitoring view
- Allow push buttons to be placed across rails
- Add 'Show Pins' view to app version
- Add schematic feature
- Add manual
- Add more functions and components
- Add more examples
- PC integration
In-app purchases
primr
No in-app purchases
CRUMB
No in-app purchases
