# DrPhos' Ionic Compounds vs Skilled Trades iCert Prep

The clearest difference is price: Skilled Trades iCert Prep at Free against DrPhos' Ionic Compounds's $0.99. Skilled Trades iCert Prep also leads on iOS requirement (14.0 vs 17.0). On ads, in-app purchases and device support there is nothing between them.

Skilled Trades iCert Prep is free to download; DrPhos' Ionic Compounds costs $0.99 up front. DrPhos' Ionic Compounds sells 11 one-off in-app purchases and Skilled Trades iCert Prep sells 3 in-app purchases, starting at $34.99 per 3 months. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | DrPhos' Ionic Compounds | Skilled Trades iCert Prep |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | **[4.9 (8 ratings)](https://appshunter.io/ios/app/drphos-ionic-compounds/id6473097401/reviews)** | — |
| Number of ratings | **8** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | — |
| Monetization | Paid | — |
| Size | 15 MB | 113 MB |
| Requires iOS | 17.0 | **14.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Monte L Helm](https://appshunter.io/developer/1715082616) | [iCert Inc.](https://appshunter.io/developer/1650970619) |

## What reviewers say

### DrPhos' Ionic Compounds

[App page](https://appshunter.io/ios/app/drphos-ionic-compounds/id6473097401)

This app helps students learn and practice forming correct chemical formulas for ionic compounds. It supports a wide range of ions, including polyatomic ones, and dynamically generates formulas with proper subscripts and parentheses. It's designed to reinforce naming rules and charge balancing through an interactive interface.

**Highlights:** Extensive cation and anion list, Support for polyatomic ions, Real-time formula generation, Subscript and parenthesis formatting, Reinforces naming rules, Charge balancing practice

**Features:** macOS Compatibility

**In-app purchases (11)**

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


### Skilled Trades iCert Prep

[App page](https://appshunter.io/ios/app/skilled-trades-icert-prep/id6581486443)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 3-Month Resource & Exam Access | $34.99 | per 3 months |
| 6-Month Resource & Exam Access | $49.99 | per 6 months |
| Annual Resource & Exam Access | $79.99 | per year |


## Frequently asked questions

### Is DrPhos' Ionic Compounds free?

DrPhos' Ionic Compounds costs $0.99, and also offers in-app purchases.

### Is Skilled Trades iCert Prep free?

Skilled Trades iCert Prep is free to download, with in-app purchases available.

### Do DrPhos' Ionic Compounds or Skilled Trades iCert Prep have ads?

Neither DrPhos' Ionic Compounds nor Skilled Trades iCert Prep 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.*