# Plot Calculator vs PrepLex

The clearest difference is in-app purchases: Plot Calculator at none against PrepLex's 3. Plot Calculator also leads on ads (none vs shown) and iOS requirement (10.2 vs 18.0). On price, update cadence and device support there is nothing between them.

Both are free to download. PrepLex sells 3 in-app purchases, starting at $1.99 per 7 days. Plot Calculator asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 8, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Plot Calculator | PrepLex |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | Every 2 months |
| Size | 13 MB | 13 MB |
| Requires iOS | **10.2** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Oklahoma State University](https://appshunter.io/developer/393442180) | [Ilker KARAMANLI](https://appshunter.io/developer/1838988018) |

## What reviewers say

### Plot Calculator

[App page](https://appshunter.io/ios/app/plot-calculator/id1246269450)

**Features:** macOS Compatibility

**In-app purchases:** none


### PrepLex

[App page](https://appshunter.io/ios/app/preplex-vocabulary-builder/id6754010143)

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Premium | $1.99 | per 7 days |
| Monthly Premium | $3.99 | per month |
| Yearly Premium | $19.99 | per year |


## Frequently asked questions

### Is Plot Calculator free?

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

### Is PrepLex free?

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

### Do Plot Calculator or PrepLex have ads?

PrepLex shows ads; Plot Calculator does not.

### Which is updated more often, Plot Calculator or PrepLex?

Plot Calculator ships an update every 2 months, and PrepLex every 2 months. Most recently, Plot Calculator was updated on October 8, 2026 and PrepLex on October 2, 2026.

---

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