# i vs RF calculator & Smith Chart

The clearest difference is in-app purchases: i at none against RF calculator & Smith Chart's 1. i also leads on update cadence (every 2 months vs every 4 months). RF calculator & Smith Chart's advantage is iOS requirement (15.0 vs 17.6). On price, ads and device support there is nothing between them.

Both are free to download. RF calculator & Smith Chart sells 1 one-off in-app purchase. i asks for nothing beyond the download.

i ships an update every 2 months, RF calculator & Smith Chart every 4 months. The most recent releases landed on October 30, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | i | RF calculator & Smith Chart |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.0 (1 ratings)](https://appshunter.io/ios/app/rf-calculator-and-smith-chart/id6757265018/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 4 months |
| Size | 34 MB | 31 MB |
| Requires iOS | 17.6 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [IFE Aufbereitungstechnik GmbH](https://appshunter.io/developer/1616801396) | [Anas Abubakar](https://appshunter.io/developer/1581534101) |

## What reviewers say

### i

[App page](https://appshunter.io/ios/app/i-step-vibrosense/id1670367375)

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

**In-app purchases:** none


### RF calculator & Smith Chart

[App page](https://appshunter.io/ios/app/rf-calculator-and-smith-chart/id6757265018)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| upgrade to pro | $3.99 | one-time |


## Frequently asked questions

### Is i free?

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

### Is RF calculator & Smith Chart free?

RF calculator & Smith Chart is free to download, with in-app purchases available.

### Do i or RF calculator & Smith Chart have ads?

Neither i nor RF calculator & Smith Chart shows ads.

### Which is updated more often, i or RF calculator & Smith Chart?

i ships an update every 2 months, and RF calculator & Smith Chart every 4 months. Most recently, i was updated on October 30, 2026 and RF calculator & Smith Chart on November 5, 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.*