# Sleep Cue vs Curl

The clearest difference is update cadence: Sleep Cue at every 3 months against Curl's every 26 months. Sleep Cue also leads on iOS requirement (11.0 vs 13.0). 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.

Sleep Cue ships an update every 3 months, Curl every 26 months. The most recent releases landed on October 10, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Sleep Cue | Curl |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/sleep-cue/id1508045969/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 26 months |
| Monetization | Free | — |
| Size | 157 MB | 48 MB |
| Requires iOS | **11.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Enchanted Wave LLC](https://appshunter.io/developer/1452734801) | [Curl-ish GmbH](https://appshunter.io/developer/1616656297) |

## What reviewers say

### Sleep Cue

[App page](https://appshunter.io/ios/app/sleep-cue/id1508045969)

This app serves as an interactive companion for a wireless brainwave headband. It displays real-time EEG signals and brainwave power spectrograms, enabling users to trigger custom cues based on sleep stages and brainwave activity for lucid dreaming.

**Highlights:** Real-time EEG signal viewing, Brainwave power spectrogram, Customizable cue triggering, Lucid dream induction techniques, Research collaboration opportunities

**Features:** macOS Compatibility

**In-app purchases:** none


### Curl

[App page](https://appshunter.io/ios/app/curl-ish/id1616655785)

**Features:** macOS Compatibility, Apple Wallet

**In-app purchases:** none


## Frequently asked questions

### Is Sleep Cue free?

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

### Is Curl free?

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

### Do Sleep Cue or Curl have ads?

Neither Sleep Cue nor Curl shows ads.

### Which is updated more often, Sleep Cue or Curl?

Sleep Cue ships an update every 3 months, and Curl every 26 months. Most recently, Sleep Cue was updated on October 10, 2026 and Curl on October 2, 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.*