# OTR Diagnostics vs LightningVolt

The clearest difference is update cadence: OTR Diagnostics at weekly against LightningVolt's every 6 weeks. LightningVolt's advantage is iOS requirement (12.0 vs 17.6). On price, ads, in-app purchases and device support there is nothing between them.

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

OTR Diagnostics ships an update weekly, LightningVolt every 6 weeks. Both last shipped on November 3, 2026.

## The numbers

| Metric | OTR Diagnostics | LightningVolt |
| --- | --- | --- |
| 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 6 weeks |
| Monetization | Free | — |
| Size | 268 MB | 28 MB |
| Requires iOS | 17.6 | **12.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [OTR Performance](https://appshunter.io/developer/1508165884) | [Roadwarrior Inc.](https://appshunter.io/developer/1712729585) |

## 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


### LightningVolt

[App page](https://appshunter.io/ios/app/lightningvolt/id6469853871)

**In-app purchases:** none


## Frequently asked questions

### Is OTR Diagnostics free?

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

### Is LightningVolt free?

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

### Do OTR Diagnostics or LightningVolt have ads?

Neither OTR Diagnostics nor LightningVolt shows ads.

### Which is updated more often, OTR Diagnostics or LightningVolt?

OTR Diagnostics ships an update weekly, and LightningVolt every 6 weeks. Most recently, OTR Diagnostics was updated on November 3, 2026 and LightningVolt on November 3, 2026.

---

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