# OTR Diagnostics vs Percently Quick Calculator

OTR Diagnostics and Percently Quick Calculator are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

OTR Diagnostics ships an update weekly, Percently Quick Calculator every 8 days. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | OTR Diagnostics | Percently Quick Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (99 ratings)](https://appshunter.io/ios/app/otr-diagnostics/id1508165885/reviews)** | — |
| Number of ratings | **99** | — |
| Positive reviews | 55.2% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Weekly** | Every 8 days |
| Monetization | Free | — |
| Size | 268 MB | 2 MB |
| Requires iOS | 17.6 | **17.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [OTR Performance](https://appshunter.io/developer/1508165884) | [Sacred Pathway LLC](https://appshunter.io/developer/1893663069) |

## What reviewers say

### OTR Diagnostics

[App page](https://appshunter.io/ios/app/otr-diagnostics/id1508165885)

This diagnostic tool helps heavy-duty truck owners understand and resolve fault codes, perform crucial maintenance tasks like regens, and monitor live engine data. It aims to reduce downtime and avoid costly dealer visits by empowering users with detailed insights and control over their vehicle's systems.

**Highlights:** Reset active and inactive fault codes, Perform forced DPF/SCR regens, Understand fault codes in plain language, Monitor live engine data, Track fault code history, Bi-directional commands for repairs

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 💰 Saves money on repairs
- 🛠️ Clears fault codes
- 🔄 Performs forced regens
- ✅ Works with various engines
- 👍 Easy to use

**What reviewers complain about**

- 💸 Overpriced
- 🐛 Buggy and unstable app
- 🔌 Frequent Bluetooth disconnects
- 📉 Updates cause problems
- ❌ Some features disappeared after updates

**Reported bugs**

- App constantly disconnects from device
- Generic code option disappeared
- Forced regen is no longer consistent
- AI assistant not working
- App asks to do things not available in app

**Requested features**

- Remember email address for login
- Allow offline functionality without data connection
- Add option to change speed
- More detailed diagnostic information
- Allow basic subscription to work on multiple VINs


### Percently Quick Calculator

[App page](https://appshunter.io/ios/app/percently-quick-calculator/id6783191768)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is OTR Diagnostics free?

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

### Is Percently Quick Calculator free?

Percently Quick Calculator is free to download, with no in-app purchases.

### Do OTR Diagnostics or Percently Quick Calculator have ads?

Neither OTR Diagnostics nor Percently Quick Calculator shows ads.

### Which is updated more often, OTR Diagnostics or Percently Quick Calculator?

OTR Diagnostics ships an update weekly, and Percently Quick Calculator every 8 days. Most recently, OTR Diagnostics was updated on November 3, 2026 and Percently Quick Calculator on October 31, 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.*