iEngineer vs Technical Pocket Guide (STT)
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
Technical Pocket Guide (STT)
This mobile reference guide offers essential technical knowledge for students, engineers, and technicians. It features a comprehensive search function, customizable bookmarks, and offline access, making it a convenient tool for daily work.
- Mobile technical reference
- Full-text search
- Table of contents with links
- Customizable bookmarks and notes
- Email content sharing
- Offline functionality
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Schaeffler’s Technical Pocket Guide in a new edition! Schaeffler's Technical Pocket Guide provides students of technical degree programs, engineers, and technicians alike a compact and mobile reference work to help them in their day-to-day work. Several chapters have been updated in the new edition and the chapters about tolerances and design elements have been expanded. An overview of the individual features is given below: - You can read the STT on your mobile device - Full-text search function - Table of contents with links to the chapters - Individual bookmarks and notes can be saved - Content can be sent quickly and easily by e-mail - Full offline functionality and contact with Schaeffler Get hold of this technical knowledge as a reference work on your mobile device now!
Screenshots
Verdict
The clearest difference is in-app purchases: Technical Pocket Guide (STT) at none against iEngineer's 1. Technical Pocket Guide (STT) also leads on rating (5.0 vs 4.6) and iOS requirement (17.0 vs 26.0). iEngineer's advantage is review sentiment (86% vs 55%) and ratings volume (200 vs 1). On price, update cadence, 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
Both are free to download. iEngineer sells 1 one-off in-app purchase. Technical Pocket Guide (STT) asks for nothing beyond the download.
Technical Pocket Guide (STT) holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: iEngineer has 200 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 86% of iEngineer's written reviews are positive against 55% of Technical Pocket Guide (STT)'s, so the app with the better star average is not the one people write more warmly about.
iEngineer ships an update every 5 months, Technical Pocket Guide (STT) every 9 months. The most recent releases landed on October 29, 2026 and October 23, 2026 respectively.
| Parameter | iEngineer | Technical Pocket Guide (STT) |
|---|---|---|
| Price | Free | Free |
| Rating | 4.6 (200 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 85.5% of reviews — better | 55.0% of reviews |
| Number of ratings | 200 — better | 1 |
| Update frequency | Every 5 months — better | Every 9 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 26.0 | 17.0 — better |
| Further details — not scored | ||
| Size | 12 MB | 55 MB |
| Age rating | 4+ | 4+ |
| Developer | Perfectly Simple Apps LLC | Schaeffler Technologies GmbH & Co. KG |
Customer experience
iEngineer
Technical Pocket Guide (STT)
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
Technical Pocket Guide (STT)
Not enough reviews yet to summarise bugs or requests.
In-app purchases
iEngineer
- Metric Screws$1.99
Technical Pocket Guide (STT)
No in-app purchases
