# VPD Tool vs WakeRally

The clearest difference is price: WakeRally at Free against VPD Tool's $0.49. VPD Tool's advantage is in-app purchases (none vs 3) and iOS requirement (18.5 vs 26.0). On ads and device support there is nothing between them.

WakeRally is free to download; VPD Tool costs $0.49 up front. WakeRally sells 3 in-app purchases, starting at $0.99 per month. VPD Tool asks for nothing beyond the download.

## The numbers

| Metric | VPD Tool | WakeRally |
| --- | --- | --- |
| Price | $0.49 | **Free** |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/vpd-tool/id6751213834/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | — |
| Monetization | Paid | — |
| Size | 2 MB | 12 MB |
| Requires iOS | **18.5** | 26.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Nicholas Hwang](https://appshunter.io/developer/1802240669) | [Wuhan Jiange Technology Co., Ltd.](https://appshunter.io/developer/1848764264) |

## What reviewers say

### VPD Tool

[App page](https://appshunter.io/ios/app/vpd-tool/id6751213834)

This utility app helps growers understand Vapor Pressure Deficit (VPD) for optimal plant growth. It features an interactive heatmap and stage presets to guide environmental adjustments. Calculations are performed on-device for privacy.

**Highlights:** Interactive VPD heatmap, Stage-specific VPD ranges, Leaf and Air VPD calculation, Home and Lock Screen widgets, On-device calculations, CSV log export

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

**In-app purchases:** none


### WakeRally

[App page](https://appshunter.io/ios/app/wakerally-task-alarm-clock/id6808646032)

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| WakeRally Pro Monthly | $0.99 | per month |
| WakeRally Pro Yearly | $4.99 | per year |
| WakeRally Pro Lifetime | $9.99 | one-time |


## Frequently asked questions

### Is VPD Tool free?

VPD Tool costs $0.49, with no in-app purchases.

### Is WakeRally free?

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

### Do VPD Tool or WakeRally have ads?

Neither VPD Tool nor WakeRally shows ads.

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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.*