# Base PRO vs WTDI

The clearest difference is price: Base PRO at Free against WTDI's $2.49. Base PRO also leads on iOS requirement (12 vs 14.0). WTDI's advantage is update cadence (every 6 weeks vs every 4 months). On ads, in-app purchases and device support there is nothing between them.

Base PRO is free to download; WTDI costs $2.49 up front. Neither carries in-app purchases, so what you see is what you pay.

Base PRO ships an update every 4 months, WTDI every 6 weeks. The most recent releases landed on October 22, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Base PRO | WTDI |
| --- | --- | --- |
| Price | **Free** | $2.49 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 6 weeks** |
| Monetization | Paid | — |
| Size | 9 MB | 4 MB |
| Requires iOS | **12** | 14.0 |
| Devices | iPhone, iPad, iPod, Mac | **iPhone, iPad, iPod, Mac, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Nic Kolbe](https://appshunter.io/developer/512550641) | [Thomas Coomer](https://appshunter.io/developer/1006451481) |

## What reviewers say

### Base PRO

[App page](https://appshunter.io/ios/app/base-pro/id1482739496)

This app simplifies base conversions from Base 2 to Base 20 with precision and clarity. It offers interactive visual explanations of number systems, making it ideal for students and educators learning computer science and digital computation.

**Highlights:** Base conversions (2-20), Precision and clarity, Visual Flow Function, Interactive learning, Full-screen mode, Adjustable sizing

**Features:** Vision Pro support

**In-app purchases:** none


### WTDI

[App page](https://appshunter.io/ios/app/wtdi-date-calculator/id1627207359)

**Features:** Apple Watch app, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Base PRO free?

Base PRO is free to download, with no in-app purchases.

### Is WTDI free?

WTDI costs $2.49, with no in-app purchases.

### Do Base PRO or WTDI have ads?

Neither Base PRO nor WTDI shows ads.

### Which is updated more often, Base PRO or WTDI?

Base PRO ships an update every 4 months, and WTDI every 6 weeks. Most recently, Base PRO was updated on October 22, 2026 and WTDI on October 10, 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.*