Comparison

Resistor Tools Pro vs Transformer Calculator Plus

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Resistor Tools Pro

This utility app offers a suite of tools for calculating and finding resistor combinations. It's designed for electronics enthusiasts and professionals needing to determine series, parallel, and voltage divider configurations. Save and share your calculations easily.

Highlights
  • Calculate series/parallel resistance
  • Find resistor combinations for desired resistance
  • Voltage divider ratio and value calculation
  • Inverting amplifier gain calculation
  • Save combinations to CSV
  • Share via AirDrop
  • Upload CSV to iCloud Drive
Read full description

This app is a collection of resistor calculators. It is suitable for hobbyist or electronic engineer. * Calculate resistance of 2 resistors in series or parallel * Find out combinations of 2 resistors in series/parallel making a desired resistance * Calculate ratio of R1/R2 and voltage divider * Find out resistor values of making voltage divider ratio * Find out resistor values of making inverting amplifier gain * Save combination values in CSV file * Share document via AirDrop * Upload CSV file to iCloud Drive (For iOS8 or later)

About

Transformer Calculator Plus

This utility app calculates key parameters for transformers, including voltage, current, and turns ratio. It helps determine if a transformer is step-up or step-down, essential for power conversion applications.

Highlights
  • Calculate primary and secondary voltage
  • Calculate primary and secondary current
  • Calculate transformer turns ratio
  • Determine step-up or step-down transformer
  • Supports AC voltage calculations
Features
Read full description

Transformer Calculator calculate any parameter within the transformer equation, including primary and secondary voltage, current, and turns. Transformer Calculations Include: Transformer Turns Ratio – Current and Turns Transformer Turns Ratio – Voltage and Turns Transformer Turns Ratio – Voltage and Current The result will indicate whether the transformer is step-up or step-down. Transformers are primarily used as power converters. The two types—step-up and step-down—operate on the same principle but in opposite directions. A step-up transformer converts a lower AC voltage to a higher voltage, while a step-down transformer reduces a higher AC voltage to a lower level. For example, if a country uses 110 V power, a step-up transformer converts it to 220 V, and a step-down transformer does the reverse. Both work with alternating current (AC). A transformer consists of a soft iron core with two coils wound around it, which are not electrically connected. These coils may be wound on separate limbs of the iron core or placed one over the other. The coil to which the alternating voltage is applied is called the primary coil or primary winding. When an alternating voltage is applied, the resulting alternating current in the primary winding generates a changing magnetic field. This changing field induces an alternating current in the secondary coil. The magnitude of the induced voltage depends on the number of turns in the secondary winding. All transformers have a nameplate rating. It is best to operate them within the voltage limits specified. Using a step-down transformer below its rated limit can support a wide range of applications, but exceeding the specified limit is dangerous and may cause electrical failure. The relationship between voltage, current, and the number of turns in each coil is given by: Vp/Vs = Np/Ns = Is/Ip Where: Vp – Primary voltage Vs – Secondary voltage Np – Primary turns Ns – Secondary turns Ip – Primary current Is – Secondary current Thank you for your support, and please visit nitrio.com for more apps for your iOS devices.

Screenshots

Resistor Tools Pro4 screens
Transformer Calculator Plus4 screens

Verdict

The call

The clearest difference is rating: Resistor Tools Pro at 4.0 against Transformer Calculator Plus's 3.3. Resistor Tools Pro also leads on update cadence (every 2 months vs every 45 months) and price ($0.99 vs $2.99). Transformer Calculator Plus's advantage is ratings volume (4 vs 1). 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

CostPrice · In-app purchases · Ads · Monetization

Resistor Tools Pro costs $0.99 and Transformer Calculator Plus $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Resistor Tools Pro holds the better App Store score, 4.0 against 3.3. Both are backed by a comparable volume of ratings — 1 and 4 respectively.

UpkeepUpdate frequency

Resistor Tools Pro ships an update every 2 months, Transformer Calculator Plus every 45 months. The most recent releases landed on June 25, 2026 and September 10, 2026 respectively.

Scorecard4 real differences · 6 level
Resistor Tools Pro versus Transformer Calculator Plus: the parameters behind the verdict, then further details
ParameterResistor Tools ProTransformer Calculator Plus
Price$0.99 — better$2.99
Rating4.0 (1 ratings) — better3.3 (4 ratings)
Positive reviews—0.0% of reviews
Number of ratings14 — better
Update frequencyEvery 2 months — betterEvery 45 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.0 — better13.0
Further details — not scored
Size4 MB1 MB
Age rating4+4+
DeveloperSiu Yuen HoNitrio

Customer experience

Resistor Tools Pro

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Transformer Calculator Plus

All ratings4 ratings
Positive50.0%
Neutral0.0%
Negative50.0%
Written reviews2 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

Resistor Tools Pro

No in-app purchases

None

Transformer Calculator Plus

No in-app purchases

Questions

Is Resistor Tools Pro free?
Resistor Tools Pro costs $0.99, with no in-app purchases.
Is Transformer Calculator Plus free?
Transformer Calculator Plus costs $2.99, with no in-app purchases.
Which has better reviews, Resistor Tools Pro or Transformer Calculator Plus?
Resistor Tools Pro is rated higher. Resistor Tools Pro averages 4.0 out of 5 from 1 ratings, while Transformer Calculator Plus averages 3.3 from 4 ratings.
Do Resistor Tools Pro or Transformer Calculator Plus have ads?
Neither Resistor Tools Pro nor Transformer Calculator Plus shows ads.
Which is updated more often, Resistor Tools Pro or Transformer Calculator Plus?
Resistor Tools Pro ships an update every 2 months, and Transformer Calculator Plus every 45 months. Most recently, Resistor Tools Pro was updated on June 25, 2026 and Transformer Calculator Plus on September 10, 2026.

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