# Polnav BT bridge vs ETA321

The clearest difference is update cadence: ETA321 at weekly against Polnav BT bridge's every 2 months. Polnav BT bridge's advantage is iOS requirement (11.0 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.

Polnav BT bridge ships an update every 2 months, ETA321 weekly. Both last shipped on October 25, 2026.

## The numbers

| Metric | Polnav BT bridge | ETA321 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Weekly** |
| Size | 5 MB | 10 MB |
| Requires iOS | **11.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Polstar Technologies Inc.](https://appshunter.io/developer/393264828) | [Wing Leung Wong](https://appshunter.io/developer/6802715513) |

## What reviewers say

### Polnav BT bridge

[App page](https://appshunter.io/ios/app/polnav-bt-bridge/id1546181174)

**In-app purchases:** none


### ETA321

[App page](https://appshunter.io/ios/app/eta321-every-second-counts/id6802721196)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Polnav BT bridge free?

Polnav BT bridge is free to download, with no in-app purchases.

### Is ETA321 free?

ETA321 is free to download, with no in-app purchases.

### Do Polnav BT bridge or ETA321 have ads?

Neither Polnav BT bridge nor ETA321 shows ads.

### Which is updated more often, Polnav BT bridge or ETA321?

Polnav BT bridge ships an update every 2 months, and ETA321 weekly. Most recently, Polnav BT bridge was updated on October 25, 2026 and ETA321 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.*