# PP+ Joule Heating vs pH Test Solution

The clearest difference is device support: pH Test Solution at 3 against PP+ Joule Heating's 1. pH Test Solution also leads on iOS requirement (12.0 vs 18.0). On price, update cadence, ads and in-app purchases there is nothing between them.

PP+ Joule Heating costs $1.99 and pH Test Solution $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

PP+ Joule Heating ships an update every 31 months, pH Test Solution every 60 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | PP+ Joule Heating | pH Test Solution |
| --- | --- | --- |
| Price | $1.99 | $1.99 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 31 months** | Every 60 months |
| Size | 125 MB | 228 MB |
| Requires iOS | 18.0 | **12.0** |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Polyhedron Learning Media, Inc.](https://appshunter.io/developer/458882328) | [VIRTUAL FILAMENTS PRIVATE LIMITED](https://appshunter.io/developer/1474217212) |

## What reviewers say

### PP+ Joule Heating

[App page](https://appshunter.io/ios/app/pp-plus-joule-heating/id804719524)

**Features:** macOS Compatibility

**In-app purchases:** none


### pH Test Solution

[App page](https://appshunter.io/ios/app/ph-test-solution-edutech-era/id1542911614)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is PP+ Joule Heating free?

PP+ Joule Heating costs $1.99, with no in-app purchases.

### Is pH Test Solution free?

pH Test Solution costs $1.99, with no in-app purchases.

### Do PP+ Joule Heating or pH Test Solution have ads?

Neither PP+ Joule Heating nor pH Test Solution shows ads.

### Which is updated more often, PP+ Joule Heating or pH Test Solution?

PP+ Joule Heating ships an update every 31 months, and pH Test Solution every 60 months. Most recently, PP+ Joule Heating was updated on November 1, 2026 and pH Test Solution on November 3, 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.*