iAlignTest vs Straightness
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
iAlignTest
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An interactive reference tool for machine shaft alignment. It provides the common reference tables, specifications and charts for shaft alignment tolerance. Three main standards are included: 1- NASA Precision Alignment Specs (Ames Policy Directive APD 8830.1) 1.a) Alignment Tolerance for Soft Foot 1.b) Alignment Tolerance for Short Coupling: Horizontal and Angular 1.c) Alignment Tolerance for couplings with spacers 2- Common Tolerance Table with the RPM input for Angular, Parallel, and Spacer Shaft cases User selects the RPM range, enters alignment values and sees the alignment condition and tolerance range for the machine. 3- Interactive Alignment Tolerance Chart with three regions: Excellent, Acceptable, and Unacceptable. User enters RPM, offset and angles in both horizontal and vertical directions, and interactively sees the condition of the machine in the chart Features: - Shaft Alignment Specification: NASA Standard - Interactive Shaft Alignment Tolerance Table - Interactive Shaft Alignment Tolerance Chart in mm and inch - Email the results DISCLAIMER: iAlignTest is intended for educational purposes. Although the references in this App are made with great care, however it may contain errors and inaccuracies. Using the results of this App is the responsibility of the user.
Straightness
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This companion app performs straightness measurements using the AT-400 Ultimate on typical applications such as guides. The app guides the user through the complete measurement and alignment process when using the Bluetooth® connected ACOEM M9 sensor. This offers extensive, easy-to-use straightness measurement capability. The PDF Report function provides fast on-site reporting capability by converting saved measurement reports into PDF files. ---- Note: This app works only with the ACOEM AT-400 with the M9 sensor ---- Key Features: - Connected using Bluetooth® - GuideU: Our patented icon-based and color-coded adaptive user interface - New 3D views of the result - Create an instant PDF-report Visit the website www.acoem.com for more information on alignment in general, the ACOEM tools and support of the app.
Screenshots
Verdict
The clearest difference is update cadence: Straightness at every 2 months against iAlignTest's every 32 months. Straightness also leads on iOS requirement (12.0 vs 15.0). On price, ads, in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.
iAlignTest ships an update every 32 months, Straightness every 2 months. The most recent releases landed on September 22, 2026 and September 17, 2026 respectively.
| Parameter | iAlignTest | Straightness |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 32 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 15.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 8 MB | 59 MB |
| Age rating | 4+ | 4+ |
| Developer | Motionics LLC | ACOEM Group |
In-app purchases
iAlignTest
No in-app purchases
Straightness
No in-app purchases
Questions
Is iAlignTest free?
Is Straightness free?
Do iAlignTest or Straightness have ads?
Which is updated more often, iAlignTest or Straightness?
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