555 Calc vs HE.FMX
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.
HE.FMX
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This App is used with the HE-FMX Hardware, let you measure thickness from 0 to 12mm. Measurements are made when its magnetic probe is held or scanned on one side of the test surface and a small target magnetic ball is dropped inside the instrument. The probe measures the distance between the probe tip and target ball. The user can use one of the two balls provided (6,0 or 10,0 mm in diameter) according to the needs, the maximum measurable thickness is 12 mm, the accuracy is 0.01mm. The measurement is continuous and, thanks to the unique calibration system, any soft material can be applied to the sensor to prevent it from scratching instruments already varnished.
Screenshots
Verdict
The clearest difference is ads: HE.FMX at none against 555 Calc's shown. 555 Calc's advantage is update cadence (every 20 months vs every 42 months). On price, in-app purchases, device support and iOS requirement 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. Neither carries in-app purchases, so what you see is what you pay.
555 Calc ships an update every 20 months, HE.FMX every 42 months. The most recent releases landed on October 28, 2026 and October 26, 2026 respectively.
| Parameter | 555 Calc | HE.FMX |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (3 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 3 — better | — |
| Update frequency | Every 20 months — better | Every 42 months |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Ad-supported | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 11.0 | 11.0 |
| Further details — not scored | ||
| Size | 18 MB | 37 MB |
| Age rating | 4+ | 4+ |
| Developer | Jibiki Works | Guido brancalion |
In-app purchases
555 Calc
No in-app purchases
HE.FMX
No in-app purchases
Questions
Is 555 Calc free?
Is HE.FMX free?
Do 555 Calc or HE.FMX have ads?
Which is updated more often, 555 Calc or HE.FMX?
Other comparisons
