# CallStar vs SBK Flex

The clearest difference is update cadence: SBK Flex at every 4 weeks against CallStar's every 4 months. CallStar's advantage is device support (3 vs 1) and iOS requirement (8.0 vs 16.0). On price, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

CallStar ships an update every 4 months, SBK Flex every 4 weeks. The most recent releases landed on October 22, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | CallStar | SBK Flex |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/callstar/id533366309/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 4 weeks** |
| Monetization | Free | — |
| Size | 14 MB | 117 MB |
| Requires iOS | **8.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 12+ |
| Developer | [Nordcom Oy](https://appshunter.io/developer/533366312) | [SBK Telecom](https://appshunter.io/developer/1450446983) |

## What reviewers say

### CallStar

[App page](https://appshunter.io/ios/app/callstar/id533366309)

Manage inbound business calls, utilize versatile number services, and access teleconference features directly from your mobile device. Optimize outbound calls with Least Cost Routing. Requires configuration from a CallStar service provider.

**Highlights:** Inbound call management, Versatile number service, Teleconference features, Least Cost Routing (LCR), FLCR for international calls

**Features:** macOS Compatibility

**In-app purchases:** none


### SBK Flex

[App page](https://appshunter.io/ios/app/sbk-flex/id6747500332)

**Features:** Siri integration, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is CallStar free?

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

### Is SBK Flex free?

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

### Do CallStar or SBK Flex have ads?

Neither CallStar nor SBK Flex shows ads.

### Which is updated more often, CallStar or SBK Flex?

CallStar ships an update every 4 months, and SBK Flex every 4 weeks. Most recently, CallStar was updated on October 22, 2026 and SBK Flex on October 25, 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.*