# phase estimation algorithm vs Quantum Retriever

The clearest difference is update cadence: Quantum Retriever at every 9 days against phase estimation algorithm's monthly. 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.

phase estimation algorithm ships an update monthly, Quantum Retriever every 9 days. The most recent releases landed on September 15, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | phase estimation algorithm | Quantum Retriever |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | **Every 9 days** |
| Size | 12 MB | 27 MB |
| Requires iOS | 16.0 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Sungjun Kim](https://appshunter.io/developer/1602461985) | [James Beach](https://appshunter.io/developer/1879362223) |

## What reviewers say

### phase estimation algorithm

[App page](https://appshunter.io/ios/app/phase-estimation-algorithm/id6469448415)

**Features:** macOS Compatibility

**In-app purchases:** none


### Quantum Retriever

[App page](https://appshunter.io/ios/app/quantum-retriever/id6759576344)

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

**In-app purchases:** none


## Frequently asked questions

### Is phase estimation algorithm free?

phase estimation algorithm is free to download, with no in-app purchases.

### Is Quantum Retriever free?

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

### Do phase estimation algorithm or Quantum Retriever have ads?

Neither phase estimation algorithm nor Quantum Retriever shows ads.

### Which is updated more often, phase estimation algorithm or Quantum Retriever?

phase estimation algorithm ships an update monthly, and Quantum Retriever every 9 days. Most recently, phase estimation algorithm was updated on September 15, 2026 and Quantum Retriever on September 9, 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.*