# Null Fasting vs GRBX

The clearest difference is in-app purchases: Null Fasting at none against GRBX's 4. GRBX's advantage is rating (4.8 vs 4.5) and device support (3 vs 1). On price, review sentiment, update cadence and ads there is nothing between them.

Both are free to download. GRBX sells 4 in-app purchases, starting at $4.99 per month. Null Fasting asks for nothing beyond the download.

GRBX holds the better App Store score, 4.8 against 4.5. Both are backed by a comparable volume of ratings — 2 and 6 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Null Fasting ships an update weekly, GRBX every 5 days. The most recent releases landed on October 24, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | Null Fasting | GRBX |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (2 ratings)](https://appshunter.io/ios/app/null-fasting/id6743633464/reviews) | **[4.8 (6 ratings)](https://appshunter.io/ios/app/grbx-car-maintenance-tracker/id6761734462/reviews)** |
| Number of ratings | 2 | **6** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Weekly | **Every 5 days** |
| Monetization | **Free** | Ad-supported |
| Size | 21 MB | 6 MB |
| Requires iOS | 17.6 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [YMMV](https://appshunter.io/developer/1224453829) | [Gearbox Technologies LLC](https://appshunter.io/developer/1891160733) |

## What reviewers say

### Null Fasting

[App page](https://appshunter.io/ios/app/null-fasting/id6743633464)

This app helps you track intermittent fasting with flexible protocols, detailed statistics, and motivational tools. It integrates with health platforms and offers personalized goal setting for a healthier lifestyle.

**Highlights:** Flexible fasting protocols (16:8, OMAD, custom), Intelligent tracking with timers and notifications, Comprehensive statistics and progress analysis, Apple Health integration, Milestone tracking and educational content, Personalized motivation and goal setting, Smart scheduling and reminders

**Features:** macOS Compatibility

**In-app purchases:** none


### GRBX

[App page](https://appshunter.io/ios/app/grbx-car-maintenance-tracker/id6761734462)

This tool helps you proactively manage vehicle ownership by tracking maintenance history and providing predictive insights. It evolves with your car, offering advanced analytics and an AI assistant to optimize your vehicle's lifespan and your decision-making.

**Highlights:** Predictive maintenance insights, Vehicle maintenance history tracking, Advanced analytics, Document organization, AI assistant for idea generation, Proactive vehicle care strategy

**Features:** macOS Compatibility

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| GRBX Pro | $4.99 | per month |
| GRBX Family | $9.99 | per month |
| GRBX Pro Annual | $49.99 | per year |
| GRBX Family Annual | $99.99 | per year |


## Frequently asked questions

### Is Null Fasting free?

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

### Is GRBX free?

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

### Which has better reviews, Null Fasting or GRBX?

GRBX is rated higher. Null Fasting averages 4.5 out of 5 from 2 ratings, while GRBX averages 4.8 from 6 ratings.

### Do Null Fasting or GRBX have ads?

Neither Null Fasting nor GRBX shows ads.

### Which is updated more often, Null Fasting or GRBX?

Null Fasting ships an update weekly, and GRBX every 5 days. Most recently, Null Fasting was updated on October 24, 2026 and GRBX on October 19, 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.*