Comparison

ActiveOBD vs TrafoCalc

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

Head to head
About

ActiveOBD

This app functions as an OBDII scanner, offering specialized support for Subaru vehicles (MY2012+). It provides basic parameter readings for free, with a subscription unlocking advanced features like trouble code reading and data logging.

Highlights
  • OBDII scanning
  • Subaru-specific support (MY2012+)
  • CVT Oil Temperature reading
  • AWD duty (%) parameter reading
  • Trouble code reading (full version)
  • Data logging (full version)
  • Graphs building (full version)
Features
Read full description

The OBDII scanner app with a special support of Subaru (MY2012+) make. It's the next-generation product based on our well-known "ActiveOBD for Subaru" app bringing its best features to iOS users. A compatible OBD adapter is required. Premium-level adapters supported (best speed and stability): - OBDLink MX+; - OBDLink CX; - vLinker MC+. Entry-level adapters supported (moderate speed, good stability): - Vgate iCar Pro Bluetooth 4.0 (BLE). Other adapters supported: - Viecar Bluetooth 4.0 (BLE), Vgate iCar Pro WiFi, Veepeak OBDCheck BLE+, KONNWEI. We do NOT support the majority of cheap ELM327 v2.1 clones. The basic free version already includes CVT Oil Temperature, CVT ratio and AWD duty (%) parameter readings and nice gauge screen ! Note: some of these parameters are inaccessible on some model ranges. The full version (subscription) includes extra parameters reading and features, such as graphs building, logging ("premium-level adapter" required), trouble codes reading. Note: for resource consumption optimization reason the data collection for graphs/logging activates upon accessing these functions and terminates with the current app session. Terms of Use (standard Apple Terms of Use / EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

TrafoCalc

Features
Read full description

TrafoCalc is a practical transformer calculation tool built specifically for field engineers, commissioning teams, and utility professionals. Designed for real-world use at substations and test sites, TrafoCalc provides fast, reliable calculations without spreadsheets or manual formulas. Key Features • Rated current calculation (HV & LV, 3-phase) • Transformer ratio calculation based on vector group • Full tap-changer support (Tap 1 = highest voltage) • Per-tap voltage and ratio calculation • ±0.5% ratio tolerance range for testing reference • Short-circuit current calculation • Supports common IEC vector groups (Dyn, YNd, Yy) • Clean, offline-ready interface Built for Professionals TrafoCalc follows IEC-based formulas and is suitable for: • Factory Acceptance Tests (FAT) • Site Acceptance Tests (SAT) • OLTC verification • Ratio testing reference • Substation commissioning No ads. No clutter. Just the calculations engineers actually need.

Screenshots

ActiveOBD4 screens
TrafoCalc4 screens

Verdict

The call

The clearest difference is price: ActiveOBD at Free against TrafoCalc's $0.99. ActiveOBD also leads on iOS requirement (13.0 vs 18.2). TrafoCalc's advantage is in-app purchases (none vs 1) and update cadence (every 9 days vs every 3 months). On 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

CostPrice · In-app purchases · Ads · Monetization

ActiveOBD is free to download; TrafoCalc costs $0.99 up front. ActiveOBD sells 1 in-app purchase, starting at $4.99 per month. TrafoCalc asks for nothing beyond the download.

UpkeepUpdate frequency

ActiveOBD ships an update every 3 months, TrafoCalc every 9 days. The most recent releases landed on July 23, 2026 and September 8, 2026 respectively.

Scorecard4 real differences · 6 level
ActiveOBD versus TrafoCalc: the parameters behind the verdict, then further details
ParameterActiveOBDTrafoCalc
PriceFree — better$0.99
Rating3.6 (39 ratings) — better—
Positive reviews45.5% of reviews—
Number of ratings39 — better—
Update frequencyEvery 3 monthsEvery 9 days — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.0 — better18.2
Further details — not scored
Size24 MB4 MB
Age rating4+4+
DeveloperMykhailo ZolotarovMohd Dahnial Ismail

In-app purchases

1 purchases

ActiveOBD

Subscriptions1
  • Full Version Subscription1 Month trial$4.991 Month
None

TrafoCalc

No in-app purchases

Questions

Is ActiveOBD free?
ActiveOBD is free to download, with in-app purchases available.
Is TrafoCalc free?
TrafoCalc costs $0.99, with no in-app purchases.
Do ActiveOBD or TrafoCalc have ads?
Neither ActiveOBD nor TrafoCalc shows ads.
Which is updated more often, ActiveOBD or TrafoCalc?
ActiveOBD ships an update every 3 months, and TrafoCalc every 9 days. Most recently, ActiveOBD was updated on July 23, 2026 and TrafoCalc on September 8, 2026.

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