Timer 555 Calculator vs Simple Circuit Builder
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Timer 555 Calculator
Calculate monostable and astable circuits for electronics projects. Determine pulse width and frequency, find component combinations, and save/upload data. Supports multiple languages.
- Monostable circuit pulse width calculation
- Astable circuit frequency calculation
- Component combination finder
- Save component values to CSV
- Upload CSV via AirDrop/iCloud Drive
- Multi-language support
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This app is used to calculate monostable and astable circuit. Features * Calculate pulse width of monostable circuit * Calculate frequency of astable circuit * Find out combination of components making a desire pulse width in monostable circuit * Find out combination of components making a desire frequency in astable circuit * Saving component values in CSV file * Upload generated CSV files via AirDrop or iCloud Drive * Support English, German, French, Italian, Spanish, Portuguese, Japanese, Korean, Russian
Simple Circuit Builder
This virtual lab offers a hands-on experience for learning about resistors and circuit resistance. Easily build and test series and parallel circuits, measure voltage and current, and understand the impact of component changes in real-time.
- Build circuits with up to eight components
- Five component types
- Virtual volt and amp meters
- Adjustable resistor and voltage values
- Real-time circuit analysis
- Demonstrates 'Opens' and 'Shorts'
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Description This is the BEST app to learn about Resistors and Circuit Resistance (Equivalent Resistance). This virtual lab provides an excellent environment for anyone who is interested in understanding series and parallel resistors, learning how to measure voltages across resistors, current through series and parallel circuits and solving simple circuits. Features - VERY SIMPLE and EASY TO USE, with up to eight component sections. - Component sections can easily be configured from five different types. - VIRTUAL "Hands On" experience using volt and amp meters. - Resistor values can easily be changed with a picker, keypad or using randomize button. - Circuit voltage can easily be changed from 1 to 1000 volts with a picker or a keypad. - The "Basics" screen make this app unique for the simplicity and speed of seeing the effects of "Opens" (resistor component with infinite resistance) and "Shorts" (resistor component with zero resistance). - FREE and NO ADVERTISEMENTS. - The circuit is always "LIVE" and immediately shows voltage, current and circuit resistance with any changes made to the circuit.
Screenshots
Verdict
Timer 555 Calculator and Simple Circuit Builder both sit at 3.9 stars, but that hides the real split: 100% of Timer 555 Calculator's written reviews are positive against 53% of Simple Circuit Builder's. Simple Circuit Builder's advantage is in-app purchases (none vs 1) and update cadence (every 3 weeks vs every 3 months). On price, rating, ads 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
Both are free to download. Timer 555 Calculator sells 1 one-off in-app purchase. Simple Circuit Builder asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 3.9 for Timer 555 Calculator against 4.0 for Simple Circuit Builder. Both are backed by a comparable volume of ratings — 8 and 28 respectively. Written reviews are what separate them: 100% of Timer 555 Calculator's written reviews are positive against 53% of Simple Circuit Builder's.
Timer 555 Calculator ships an update every 3 months, Simple Circuit Builder every 3 weeks. The most recent releases landed on September 24, 2026 and June 4, 2026 respectively.
| Parameter | Timer 555 Calculator | Simple Circuit Builder |
|---|---|---|
| Price | Free | Free |
| Rating | 3.9 (8 ratings) | 4.0 (28 ratings) — better |
| Positive reviews | 100.0% of reviews — better | 52.6% of reviews |
| Number of ratings | 8 | 28 — better |
| Update frequency | Every 3 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13.2 — better | 14.0 |
| Further details — not scored | ||
| Size | 3 MB | 14 MB |
| Age rating | 4+ | 4+ |
| Developer | Siu Yuen Ho | David White |
Customer experience
Timer 555 Calculator
Simple Circuit Builder
In-app purchases
Timer 555 Calculator
- Unlock Pro feature$0.99
Simple Circuit Builder
No in-app purchases
Questions
Is Timer 555 Calculator free?
Is Simple Circuit Builder free?
Which has better reviews, Timer 555 Calculator or Simple Circuit Builder?
Do Timer 555 Calculator or Simple Circuit Builder have ads?
Which is updated more often, Timer 555 Calculator or Simple Circuit Builder?
Other comparisons
