# ZappID vs Smith Charts

The clearest difference is price: ZappID at Free against Smith Charts's $3.99. ZappID also leads on update cadence (every 4 days vs every 3 weeks) and iOS requirement (12.0 vs 15.0). On ads, in-app purchases and device support there is nothing between them.

ZappID is free to download; Smith Charts costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ZappID ships an update every 4 days, Smith Charts every 3 weeks. The most recent releases landed on October 19, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | ZappID | Smith Charts |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | — | **[3.7 (3 ratings)](https://appshunter.io/ios/app/smith-charts/id1602503719/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | — | 66.7% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 3 weeks |
| Monetization | — | Paid |
| Size | 11 MB | 24 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Fredrik Petersson](https://appshunter.io/developer/555276018) | [Edoardo Orzes](https://appshunter.io/developer/1665361246) |

## What reviewers say

### ZappID

[App page](https://appshunter.io/ios/app/zappid/id1455029820)

**Features:** macOS Compatibility

**In-app purchases:** none


### Smith Charts

[App page](https://appshunter.io/ios/app/smith-charts/id1602503719)

Design matching networks, analyze device parameters, and compute stability circles with this interactive tool. Supports S parameters, various components, and offers advanced engineering features for RF design. Available in dark mode and exportable to PDF.

**Highlights:** Interactive Smith chart with drag and zoom, Design matching networks with various components, Compute stability, equi gain, and noise circles, Import S parameters from Touchstone files, Export designs to PDF, image, or file, Dark mode support, Ruler for wavelength measurement

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

**In-app purchases:** none


## Frequently asked questions

### Is ZappID free?

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

### Is Smith Charts free?

Smith Charts costs $3.99, with no in-app purchases.

### Do ZappID or Smith Charts have ads?

Neither ZappID nor Smith Charts shows ads.

### Which is updated more often, ZappID or Smith Charts?

ZappID ships an update every 4 days, and Smith Charts every 3 weeks. Most recently, ZappID was updated on October 19, 2026 and Smith Charts on October 24, 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.*