# DUO vs i

The clearest difference is update cadence: DUO at every 5 weeks against i's every 3 months. DUO also leads on iOS requirement (8.0 vs 11.0). On price, rating, review sentiment and ratings volume there is nothing between them.

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

i holds the better App Store score, 2.1 against 2.0. Both are backed by a comparable volume of ratings — 51 and 83 respectively. Written reviews complicate that: 13% of DUO's written reviews are positive against 10% of i's, so the app with the better star average is not the one people write more warmly about.

DUO ships an update every 5 weeks, i every 3 months. The most recent releases landed on October 22, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | DUO | i |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.0 (51 ratings)](https://appshunter.io/ios/app/duo-link/id982410478/reviews) | **[2.1 (83 ratings)](https://appshunter.io/ios/app/i-usb-storer/id1079877477/reviews)** |
| Number of ratings | 51 | **83** |
| Positive reviews | **13.2% of reviews** | 9.9% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 3 months |
| Monetization | Free | Free |
| Size | 31 MB | 30 MB |
| Requires iOS | **8.0** | 11.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Gopod Group Limited](https://appshunter.io/developer/975108489) | [裕雨 程](https://appshunter.io/developer/1079877476) |

## What reviewers say

### DUO

[App page](https://appshunter.io/ios/app/duo-link/id982410478)

Expand storage for your Apple devices and computers. Easily transfer files, back up contacts, and play media directly from the device. Free up space on your iPhone and iPad with this versatile storage solution.

**Highlights:** Expand iPhone/iPad storage, USB and Lightning connectors, Contact backup and restore, Independent music/video playback, Stream 1080p videos, File management

**Features:** macOS Compatibility

**In-app purchases:** none


### i

[App page](https://appshunter.io/ios/app/i-usb-storer/id1079877477)

Access and manage files on USB drives directly from your Apple device. Stream music, watch videos, and view photos stored on your USB flash drive. It also facilitates photo synchronization.

**Highlights:** Open USB Flash Drive files, Stream music, Watch videos, View photos, Sync photos, USB 3.0 card reader compatible

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- 👍 Convenient for transferring files
- 🚀 Fast file transfer between device and computer
- 💡 Useful for expanding storage on iOS devices
- 🔒 Secure data backup

**What reviewers complain about**

- 🐛 App crashes frequently
- 🐛 Compatibility issues with newer iOS versions
- 🐛 Unable to recognize external storage device
- 🐛 Buggy performance, files not transferring properly
- 👎 Poor user interface and language translation

**Reported bugs**

- App crashes when trying to export files
- External storage not detected by app
- Corrupted or lost data after file transfers
- Compatibility issues with iPhone X and newer models

**Requested features**

- Add support for landscape mode
- Improve video playback capabilities
- Allow for better file management and organization
- Provide option to change app language


## Frequently asked questions

### Is DUO free?

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

### Is i free?

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

### Which has better reviews, DUO or i?

i is rated higher. DUO averages 2.0 out of 5 from 51 ratings, while i averages 2.1 from 83 ratings.

### Do DUO or i have ads?

Neither DUO nor i shows ads.

### Which is updated more often, DUO or i?

DUO ships an update every 5 weeks, and i every 3 months. Most recently, DUO was updated on October 22, 2026 and i on October 21, 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.*