iEngineer vs Unit Converter
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
iEngineer
Access a vast database of screw and bolt information, including dimensions, material grades, and strength properties for both US and metric fasteners. Features a comprehensive drill chart, unit conversion, and customizable material displays.
- Extensive US screw database
- Metric screw database (in-app purchase)
- Detailed dimensions and material grades
- Strength, torque, and clamp force data
- Head markings and 3D head models
- Comprehensive drill chart
- Unit conversion and data export
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iEngineer is the most comprehensive database of screw/bolt information that you can find anywhere. US screws: -93 different screws from #0 to 4” -Dimensions for 9 standard head styles -74 material grades including SAE, ASTM, and other materials Metric Screws (available as in-app purchase): -210 different metric screws from M1.0 to M100 -Dimensions for 10 standard head styles for ISO, DIN, BS, and ANSI standards where available -86 material grades including 12 additional metric grades, SAE, ASTM, and other materials Displayed values for both the US and Metric screws include: -Standard dimensions -Tap sizes -Clearance hole sizes -Material strength -Recommended torque values -Clamp force -Shear force -Head markings display -3D model of head type -Standard dimensions of head type Other features: -Drill chart with 523 drill bit sizes -Fraction chart -Copy and paste data values -Fast and easy unit conversion -Ability to show/hide material grades in the interface so you only see what is relevant to you If you have any questions please contact us at support@perfectlysimpleapps.com
Unit Converter
This app offers a powerful and user-friendly unit converter with 16 categories, including currency, length, and temperature. It allows for custom unit lists and provides live exchange rate updates for 148 currencies. Unlock all features with a one-time in-app purchase.
- 16 conversion categories
- Custom unit lists
- Live currency exchange rates
- 148 world currencies supported
- User-friendly interface
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Explore our elegant and powerful unit converter with 16 categories, covering almost every unit you can think of. It's user-friendly and allows you to create custom unit lists for each category. Now featuring LIVE exchange rate updates for 148 world currencies! Categories include: Angle Area Cooking Currency Data Length Mileage Power Pressure Speed Temperature Time Volume Weight Men's shoe size Women's shoe size Note that only four categories are unlocked by default. To access all 16, simply purchase the "Pro Features" In-App. Stay connected for up-to-date currency exchange rates; an internet connection is required. Elevate your conversion experience with our versatile unit converter.
Screenshots
Verdict
iEngineer and Unit Converter both sit at 4.5 stars, but that hides the real split: 86% of iEngineer's written reviews are positive against 34% of Unit Converter's. Unit Converter's advantage is ratings volume (16K vs 201) and iOS requirement (17.6 vs 26.0). On price, rating, update cadence and ads 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. iEngineer sells 1 one-off in-app purchase and Unit Converter sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.5 for iEngineer against 4.6 for Unit Converter. That said, the two scores are not equally well evidenced: Unit Converter has 16K ratings behind it against 201, so its average is the more settled of the two. Written reviews are what separate them: 86% of iEngineer's written reviews are positive against 34% of Unit Converter's.
iEngineer ships an update every 5 months, Unit Converter every 3 months. The most recent releases landed on November 1, 2026 and November 6, 2026 respectively.
| Parameter | iEngineer | Unit Converter |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (201 ratings) | 4.6 (16K ratings) — better |
| Positive reviews | 85.5% of reviews — better | 33.9% of reviews |
| Number of ratings | 201 | 16K — better |
| Update frequency | Every 5 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 26.0 | 17.6 — better |
| Further details — not scored | ||
| Size | 12 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Perfectly Simple Apps LLC | Tue Nguyen Minh |
Customer experience
iEngineer
Unit Converter
User reviews
iEngineer
From 201 App Store ratingsWhat we love
- 🚀 Easy to navigate
- 👍 Comprehensive information
- 🔧 Useful for everyday work
- ⚙️ Essential for engineers and machinists
- 💡 Saves time compared to physical references
Room to improve
- 🐛 Occasional errors in torque and tensile strength data
- 💰 Metric information requires paid upgrade
- 🔍 Missing some thread types like NPT and BSPP
Unit Converter
From 16K App Store ratingsWhat we love
- 👍 Easy to use
- 🚀 Simple design
- 👍 Covers many units
- 👍 User-friendly layout
- 👍 Accurate conversions
Room to improve
- 🔒 Limited functionality without paying
- 🔒 Most common units locked behind paywall
- 🐛 Restore purchase not working
- 🐛 Unreliable app support
- 🔒 Conversion categories locked
Bugs and requests
iEngineer
Reported bugs
2 issues- Metric portion not working for some users
- Camera access request for no apparent reason
Requested features
4 requests- Add tap drill chart
- Include clearance hole fits
- Improve UI for larger displays
- Add French language support
Unit Converter
Reported bugs
3 issues- Conversion results not always accurate
- App freezes or crashes on some devices
- Purchased features not always accessible
Requested features
4 requests- Add calculator functionality
- Improve currency conversion
- Provide more unit categories
- Allow creating custom formulas
In-app purchases
iEngineer
- Metric Screws$1.99
Unit Converter
- Pro Features$2.99
Questions
Is iEngineer free?
Is Unit Converter free?
Which has better reviews, iEngineer or Unit Converter?
Do iEngineer or Unit Converter have ads?
Which is updated more often, iEngineer or Unit Converter?
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