# GDFF vs Navison

GDFF and Navison 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.

GDFF ships an update every 3 weeks, Navison every 2 weeks. The most recent releases landed on October 7, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | GDFF | Navison |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 2 weeks** |
| Monetization | Free | — |
| Size | 41 MB | 90 MB |
| Requires iOS | 10.0 | 10.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [松林 赵](https://appshunter.io/developer/596658260) | [BearCreeks GmbH](https://appshunter.io/developer/1569133530) |

## What reviewers say

### GDFF

[App page](https://appshunter.io/ios/app/gdff/id1468415725)

This professional-grade sonar device connects to your smartphone to provide real-time underwater data. It maps depth, temperature, terrain, and fish density up to 500 meters away and 40 meters deep.

**Highlights:** Real-time sonar technology, Underwater mapping (depth, temp, terrain), Fish density and size detection, 500m signal range, 40m maximum depth, Adjustable gain and multiple modes

**Features:** macOS Compatibility

**In-app purchases:** none


### Navison

[App page](https://appshunter.io/ios/app/navison/id1569133528)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is GDFF free?

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

### Is Navison free?

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

### Do GDFF or Navison have ads?

Neither GDFF nor Navison shows ads.

### Which is updated more often, GDFF or Navison?

GDFF ships an update every 3 weeks, and Navison every 2 weeks. Most recently, GDFF was updated on October 7, 2026 and Navison on October 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.*