# CalStack vs Senko

The clearest difference is price: Senko at Free against CalStack's $9.99. CalStack's advantage is iOS requirement (18.0 vs 27.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

Senko is free to download; CalStack costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

CalStack ships an update every 5 days, Senko every 8 days. The most recent releases landed on October 9, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | CalStack | Senko |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 days** | Every 8 days |
| Size | 20 MB | 153 MB |
| Requires iOS | **18.0** | 27.0 |
| Devices | **iPhone, iPad, Mac, Apple Watch** | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 17+ |
| Developer | [Pick Two Productions Inc](https://appshunter.io/developer/1860419697) | [ReceiptIn](https://appshunter.io/developer/488566601) |

## What reviewers say

### CalStack

[App page](https://appshunter.io/ios/app/calstack/id6789672345)

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

**In-app purchases:** none


### Senko

[App page](https://appshunter.io/ios/app/senko-ai-computer/id6813225163)

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

**In-app purchases:** none


## Frequently asked questions

### Is CalStack free?

CalStack costs $9.99, with no in-app purchases.

### Is Senko free?

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

### Do CalStack or Senko have ads?

Neither CalStack nor Senko shows ads.

### Which is updated more often, CalStack or Senko?

CalStack ships an update every 5 days, and Senko every 8 days. Most recently, CalStack was updated on October 9, 2026 and Senko on October 19, 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.*