# VPD Chart vs GrowDiary

The clearest difference is in-app purchases: GrowDiary at none against VPD Chart's 2. GrowDiary also leads on update cadence (every 9 days vs every 3 weeks). VPD Chart's advantage is ads (none vs shown) and device support (3 vs 1). On price and iOS requirement there is nothing between them.

Both are free to download. VPD Chart sells 2 in-app purchases, starting at $3.99 per month. GrowDiary asks for nothing beyond the download.

VPD Chart ships an update every 3 weeks, GrowDiary every 9 days. The most recent releases landed on October 14, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | VPD Chart | GrowDiary |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (30 ratings)](https://appshunter.io/ios/app/vpd-chart/id6470015847/reviews)** | — |
| Number of ratings | **30** | — |
| Positive reviews | 73.7% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 3 weeks | **Every 9 days** |
| Monetization | Free with in-app purchases | — |
| Size | 49 MB | 46 MB |
| Requires iOS | **15.1** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [INNOVO DEV S.R.L.](https://appshunter.io/developer/1814828527) | [GrowD soft s.r.o.](https://appshunter.io/developer/1784239247) |

## What reviewers say

### VPD Chart

[App page](https://appshunter.io/ios/app/vpd-chart/id6470015847)

This app calculates Vapor Pressure Deficit (VPD) using air temperature, relative humidity, and canopy temperature. It offers real-time charting, sensor integration, and educational tools to understand plant growth environments. Organize data by zones and visualize dew point areas.

**Highlights:** VPD calculation, Interactive VPD chart, Sensor integration, Zone organization, Dew point visualization, Grow Timeline

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| VPD Chart Plus (monthly) | $3.99 | per month |
| VPD Chart Plus (annual) | $29.99 | per year |


### GrowDiary

[App page](https://appshunter.io/ios/app/growdiary/id6739211123)

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

**In-app purchases:** none


## Frequently asked questions

### Is VPD Chart free?

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

### Is GrowDiary free?

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

### Do VPD Chart or GrowDiary have ads?

GrowDiary shows ads; VPD Chart does not.

### Which is updated more often, VPD Chart or GrowDiary?

VPD Chart ships an update every 3 weeks, and GrowDiary every 9 days. Most recently, VPD Chart was updated on October 14, 2026 and GrowDiary 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.*