# ISB vs PSO

ISB and PSO are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

ISB ships an update every 3 weeks, PSO every 2 weeks. The most recent releases landed on October 2, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | ISB | PSO |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 2 weeks** |
| Size | 35 MB | 81 MB |
| Requires iOS | 12.1 | **12** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [AziWorld Co.,Ltd](https://appshunter.io/developer/1556384050) | [Beowulf Network Inc](https://appshunter.io/developer/1590801990) |

## What reviewers say

### ISB

[App page](https://appshunter.io/ios/app/isb/id1601134322)

**Features:** macOS Compatibility

**In-app purchases:** none


### PSO

[App page](https://appshunter.io/ios/app/pso/id6469098136)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ISB free?

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

### Is PSO free?

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

### Do ISB or PSO have ads?

Neither ISB nor PSO shows ads.

### Which is updated more often, ISB or PSO?

ISB ships an update every 3 weeks, and PSO every 2 weeks. Most recently, ISB was updated on October 2, 2026 and PSO on October 6, 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.*