# PROFLEX Connect vs Knuckle Log

The clearest difference is in-app purchases: PROFLEX Connect at none against Knuckle Log's 3. PROFLEX Connect also leads on iOS requirement (12.4 vs 17.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Knuckle Log sells 3 in-app purchases, starting at $24.99 per year. PROFLEX Connect asks for nothing beyond the download.

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on October 16, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | PROFLEX Connect | Knuckle Log |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.8 (54 ratings)](https://appshunter.io/ios/app/proflex-connect/id1262287275/reviews)** | — |
| Number of ratings | **54** | — |
| Positive reviews | 37.9% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Weekly | Weekly |
| Monetization | Free | — |
| Size | 22 MB | 8 MB |
| Requires iOS | **12.4** | 17.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [ADVANCED FUEL DYNAMICS](https://appshunter.io/developer/1564136309) | [SCOTT DAVID DONALD KRELL](https://appshunter.io/developer/6792063393) |

## What reviewers say

### PROFLEX Connect

[App page](https://appshunter.io/ios/app/proflex-connect/id1262287275)

This app allows you to monitor your vehicle's fuel system performance in real-time. It displays device settings and helps locate nearby E85 fuel stations for convenient ethanol blending.

**Highlights:** Real-time device setting display, E85 station locator, Fuel ratio monitoring, Performance flex fuel system integration

**Features:** macOS Compatibility

**In-app purchases:** none


### Knuckle Log

[App page](https://appshunter.io/ios/app/knuckle-log/id6792113792)

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Basic | $24.99 | per year |
| Premium | $49.99 | per year |
| Buyer Report Unlock | $35.99 | one-time |


## Frequently asked questions

### Is PROFLEX Connect free?

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

### Is Knuckle Log free?

Knuckle Log is free to download, with in-app purchases available.

### Do PROFLEX Connect or Knuckle Log have ads?

Neither PROFLEX Connect nor Knuckle Log shows ads.

### Which is updated more often, PROFLEX Connect or Knuckle Log?

PROFLEX Connect ships an update weekly, and Knuckle Log weekly. Most recently, PROFLEX Connect was updated on October 16, 2026 and Knuckle Log on September 18, 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.*