# DrPhos Science Calculator vs PDE Pro Database Engineer

The clearest difference is in-app purchases: PDE Pro Database Engineer at none against DrPhos Science Calculator's 10. PDE Pro Database Engineer also leads on iOS requirement (15.0 vs 18.5). DrPhos Science Calculator's advantage is update cadence (every 3 weeks vs every 3 months). On price, ads and device support there is nothing between them.

Both are free to download. DrPhos Science Calculator sells 10 one-off in-app purchases. PDE Pro Database Engineer asks for nothing beyond the download.

DrPhos Science Calculator ships an update every 3 weeks, PDE Pro Database Engineer every 3 months. The most recent releases landed on September 24, 2026 and September 28, 2026 respectively.

## The numbers

| Metric | DrPhos Science Calculator | PDE Pro Database Engineer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 3 months |
| Size | 11 MB | 30 MB |
| Requires iOS | 18.5 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Monte L Helm](https://appshunter.io/developer/1715082616) | [Davy Raitt](https://appshunter.io/developer/1795318281) |

## What reviewers say

### DrPhos Science Calculator

[App page](https://appshunter.io/ios/app/drphos-science-calculator/id6747954398)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Quadratic Equation Solver | $0.99 | one-time |
| Solution Concentrations | $0.99 | one-time |
| Molar Mass Calculator | $0.99 | one-time |
| Ionic Compound Builder | $0.99 | one-time |
| Reaction Balancer | $0.99 | one-time |
| Naming Compounds | $0.99 | one-time |
| pH Calculator | $0.99 | one-time |
| Stoichiometry | $0.99 | one-time |
| Kinetics | $0.99 | one-time |
| Significant Figures Counter | $0.99 | one-time |


### PDE Pro Database Engineer

[App page](https://appshunter.io/ios/app/pde-pro-database-engineer/id6756967890)

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

**In-app purchases:** none


## Frequently asked questions

### Is DrPhos Science Calculator free?

DrPhos Science Calculator is free to download, with in-app purchases available.

### Is PDE Pro Database Engineer free?

PDE Pro Database Engineer is free to download, with no in-app purchases.

### Do DrPhos Science Calculator or PDE Pro Database Engineer have ads?

Neither DrPhos Science Calculator nor PDE Pro Database Engineer shows ads.

### Which is updated more often, DrPhos Science Calculator or PDE Pro Database Engineer?

DrPhos Science Calculator ships an update every 3 weeks, and PDE Pro Database Engineer every 3 months. Most recently, DrPhos Science Calculator was updated on September 24, 2026 and PDE Pro Database Engineer on September 28, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*