Timer 555 Calculator Pro vs Electronics Reference Toolkit
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Timer 555 Calculator Pro
Calculate parameters for monostable and astable circuits. Find component combinations for desired pulse width or frequency. Share circuit files via iCloud Drive or AirDrop.
- Calculate monostable pulse width
- Calculate astable frequency
- Find component combinations
- Adjust component tolerance
- Unlimited combinations (Pro)
- Share circuit files
Read full descriptionHide full description
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 * Share file to iCloud Drive (For iOS8 or later) * Share file via AirDrop Additional Features in the Professional Edition * Unlimited number of combinations * Allow to change tolerance * No ads
Electronics Reference Toolkit
This app provides a comprehensive suite of tools for electronics calculations and reference. It includes calculators for resistors, LEDs, capacitors, and voltage dividers, along with a unit converter and transistor database. Designed for speed and offline use, it's ideal for students, hobbyists, and engineers.
- Resistor Calculator (4/5 band)
- Ohm's Law Calculator
- LED Resistor Calculator
- Capacitor Decoder
- Voltage Divider Calculator
- Unit Converter
- Transistor Reference
Read full descriptionHide full description
ElecKit is a lightweight electronics toolkit built for fast lookups and quick calculations—perfect for students, hobbyists, and engineers. Tools included - Resistor Calculator (4/5 band) + tolerance & range - Ohm’s Law (V/I/R/P) - LED Resistor Calculator (Vs, Vf, If) - Capacitor Decoder (3-digit & EIA codes) - Voltage Divider (2 or 3 resistors) - RC/RL Time Constant with charging curve & key points (1τ…5τ) - Unit Converter (Ω, F, H, Hz + prefixes) - Battery Life Estimator (battery type, load current, duty cycle) - Transistor Reference (NPN, PNP, MOSFET) with fast search & filters Notes * Designed for speed, clean UI, and offline use. * Reference values may vary by manufacturer—always confirm with the datasheet.
Screenshots
Verdict
The clearest difference is price: Electronics Reference Toolkit at Free against Timer 555 Calculator Pro's $0.99. Electronics Reference Toolkit also leads on update cadence (fortnightly vs every 3 months) and rating (4.9 vs 4.7). Timer 555 Calculator Pro's advantage is device support (3 vs 1) and iOS requirement (13.2 vs 16.6). On ratings volume, ads and in-app purchases 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
Electronics Reference Toolkit is free to download; Timer 555 Calculator Pro costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Electronics Reference Toolkit holds the better App Store score, 4.9 against 4.7. Both are backed by a comparable volume of ratings — 3 and 7 respectively.
Timer 555 Calculator Pro ships an update every 3 months, Electronics Reference Toolkit fortnightly. The most recent releases landed on September 26, 2026 and September 19, 2026 respectively.
| Parameter | Timer 555 Calculator Pro | Electronics Reference Toolkit |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 4.7 (3 ratings) | 4.9 (7 ratings) — better |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 3 | 7 — better |
| Update frequency | Every 3 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 13.2 — better | 16.6 |
| Further details — not scored | ||
| Size | 3 MB | 7 MB |
| Age rating | 4+ | 4+ |
| Developer | Siu Yuen Ho | Ha Do Thi Thu |
Customer experience
Timer 555 Calculator Pro
Electronics Reference Toolkit
In-app purchases
Timer 555 Calculator Pro
No in-app purchases
Electronics Reference Toolkit
No in-app purchases
Questions
Is Timer 555 Calculator Pro free?
Is Electronics Reference Toolkit free?
Which has better reviews, Timer 555 Calculator Pro or Electronics Reference Toolkit?
Do Timer 555 Calculator Pro or Electronics Reference Toolkit have ads?
Which is updated more often, Timer 555 Calculator Pro or Electronics Reference Toolkit?
Other comparisons
