# Pre vs Vibration Diagnostic Service

The clearest difference is rating: Pre at 5.0 against Vibration Diagnostic Service's 2.0. Pre also leads on iOS requirement (13.0 vs 15.6). Vibration Diagnostic Service's advantage is update cadence (every 2 months vs every 7 months) and ratings volume (4 vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Pre holds the better App Store score, 5.0 against 2.0. Both are backed by a comparable volume of ratings — 1 and 4 respectively.

Pre ships an update every 7 months, Vibration Diagnostic Service every 2 months. The most recent releases landed on June 24, 2026 and September 12, 2026 respectively.

## The numbers

| Metric | Pre | Vibration Diagnostic Service |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/pre-alignment/id1499479273/reviews)** | [2.0 (4 ratings)](https://appshunter.io/ios/app/vibration-diagnostic-service/id1634378327/reviews) |
| Number of ratings | 1 | **4** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 2 months** |
| Monetization | Free | Free |
| Size | 67 MB | 120 MB |
| Requires iOS | **13.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [ACOEM Group](https://appshunter.io/developer/1495816959) | [Johnson Controls, Inc.](https://appshunter.io/developer/503559091) |

## What reviewers say

### Pre

[App page](https://appshunter.io/ios/app/pre-alignment/id1499479273)

This app guides users through pre-alignment tasks using a connected Bluetooth probe. It allows measurement and recording of run-out, bearing clearance, and soft foot, with the ability to generate instant PDF reports.

**Highlights:** Bluetooth connectivity, Icon-based adaptive user interface, Measure and record Run-Out, Measure and record Bearing Clearance, Measure and record True SoftCheck, Generate instant PDF reports

**Features:** macOS Compatibility

**In-app purchases:** none


### Vibration Diagnostic Service

[App page](https://appshunter.io/ios/app/vibration-diagnostic-service/id1634378327)

This service helps diagnose machinery health by analyzing vibratory forces emitted by HVAC and rotating equipment. It facilitates the creation of maintenance plans to prevent premature failure and downtime. Data is collected wirelessly via a connected device and analyzed by certified professionals.

**Highlights:** Vibration data collection, Wireless data acquisition, Cloud-based analysis, Predictive maintenance planning, Certified analyst reports, Email report delivery

**In-app purchases:** none


## Frequently asked questions

### Is Pre free?

Pre is free to download, with no in-app purchases.

### Is Vibration Diagnostic Service free?

Vibration Diagnostic Service is free to download, with no in-app purchases.

### Which has better reviews, Pre or Vibration Diagnostic Service?

Pre is rated higher. Pre averages 5.0 out of 5 from 1 ratings, while Vibration Diagnostic Service averages 2.0 from 4 ratings.

### Do Pre or Vibration Diagnostic Service have ads?

Neither Pre nor Vibration Diagnostic Service shows ads.

### Which is updated more often, Pre or Vibration Diagnostic Service?

Pre ships an update every 7 months, and Vibration Diagnostic Service every 2 months. Most recently, Pre was updated on June 24, 2026 and Vibration Diagnostic Service on September 12, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*