# Blue Trails vs Interval

The clearest difference is in-app purchases: Interval at none against Blue Trails's 3. Interval also leads on ads (none vs shown) and update cadence (every 4 days vs every 11 days). Blue Trails's advantage is iOS requirement (15.0 vs 26.0). On price there is nothing between them.

Both are free to download. Blue Trails sells 3 in-app purchases, starting at $14.99 per year. Interval asks for nothing beyond the download.

Blue Trails ships an update every 11 days, Interval every 4 days. The most recent releases landed on October 30, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Blue Trails | Interval |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 11 days | **Every 4 days** |
| Size | 121 MB | 87 MB |
| Requires iOS | **15.0** | 26.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, Mac, Apple TV, Apple Watch** |
| Age rating | 17+ | 4+ |
| Developer | [Blue Trails GmbH](https://appshunter.io/developer/1844606399) | [Brian Groskamp](https://appshunter.io/developer/1896650103) |

## What reviewers say

### Blue Trails

[App page](https://appshunter.io/ios/app/blue-trails-scuba-dive-log/id6753713007)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Seahorse Subscription | $14.99 | per year |
| Turtle Subscription | $54.99 | per year |
| Shark Subscription | $99.99 | per year |


### Interval

[App page](https://appshunter.io/ios/app/interval-dive-log/id6806797827)

**Features:** Apple Watch app, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Blue Trails free?

Blue Trails is free to download, with in-app purchases available.

### Is Interval free?

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

### Do Blue Trails or Interval have ads?

Blue Trails shows ads; Interval does not.

### Which is updated more often, Blue Trails or Interval?

Blue Trails ships an update every 11 days, and Interval every 4 days. Most recently, Blue Trails was updated on October 30, 2026 and Interval on October 31, 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.*