# Custom Observer App vs Blue Post Cross

The clearest difference is update cadence: Blue Post Cross at daily against Custom Observer App's every 3 weeks. Custom Observer App's advantage is iOS requirement (15.6 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

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

Custom Observer App ships an update every 3 weeks, Blue Post Cross daily. The most recent releases landed on October 12, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Custom Observer App | Blue Post Cross |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Daily** |
| Size | 151 MB | 9 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Aleut Community of St. Paul Island Tribal Government](https://appshunter.io/developer/1329178887) | [Toshinori Matsui](https://appshunter.io/developer/1870057546) |

## What reviewers say

### Custom Observer App

[App page](https://appshunter.io/ios/app/custom-observer-app/id6736385664)

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

**In-app purchases:** none


### Blue Post Cross

[App page](https://appshunter.io/ios/app/blue-post-cross/id6801400267)

**In-app purchases:** none


## Frequently asked questions

### Is Custom Observer App free?

Custom Observer App is free to download, with no in-app purchases.

### Is Blue Post Cross free?

Blue Post Cross is free to download, with no in-app purchases.

### Do Custom Observer App or Blue Post Cross have ads?

Neither Custom Observer App nor Blue Post Cross shows ads.

### Which is updated more often, Custom Observer App or Blue Post Cross?

Custom Observer App ships an update every 3 weeks, and Blue Post Cross daily. Most recently, Custom Observer App was updated on October 12, 2026 and Blue Post Cross on October 4, 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.*