555 Calc vs Pedal Builder
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
555 Calc
This utility app helps engineers and hobbyists calculate resistor values for circuits using the Timer IC 555. Simply input frequency, duty ratio, and capacitor values to get the required resistor outputs.
- Calculate resistor values
- Input frequency
- Input duty ratio
- Input capacitor value
- Timer IC 555 circuit design
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This App calculates registors value, when designing the circuit using Timer IC 555. How to (1) Input Frequency value. (2) Input Duty Ratio. (3) Input C1 Value. (4) Touch ‘Calculate’ button. (5) Registors value will be displayed. Note. * Set Duty Ratio to 50 ~ 99. * If you set Duty Ratio to 50, R1 value will be set to 0.
Pedal Builder
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This app is built to help you track your pedal builds and the inventory of parts. As you build pedals manually cross referencing your inventory is slow and tedious. With this app you can simply populate your inventory. Then add a pedal build and from the bill of materials add parts and you will be alerted if they are already in your inventory or not. Additionally, you can create a list of parts needed for that next order!
Screenshots
Verdict
The clearest difference is price: 555 Calc at Free against Pedal Builder's $1.99. 555 Calc also leads on iOS requirement (11.0 vs 16.0). Pedal Builder's advantage is ads (none vs shown) and update cadence (every 3 months vs every 20 months). On in-app purchases 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
555 Calc is free to download; Pedal Builder costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
555 Calc ships an update every 20 months, Pedal Builder every 3 months. The most recent releases landed on November 1, 2026 and October 27, 2026 respectively.
| Parameter | 555 Calc | Pedal Builder |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 4.0 (3 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 3 — better | — |
| Update frequency | Every 20 months | Every 3 months — better |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Ad-supported | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 11.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 18 MB | 26 MB |
| Age rating | 4+ | 4+ |
| Developer | Jibiki Works | John Toms |
In-app purchases
555 Calc
No in-app purchases
Pedal Builder
No in-app purchases
Questions
Is 555 Calc free?
Is Pedal Builder free?
Do 555 Calc or Pedal Builder have ads?
Which is updated more often, 555 Calc or Pedal Builder?
Other comparisons
