Sleep When I Sleep vs CerePlay
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sleep When I Sleep
This app alerts you when you're falling asleep while listening to audiobooks or podcasts. It pauses playback to help you easily find your place again. It utilizes Apple Watch health data to detect sleep and offers a reset function for continued use.
- Sleep detection alerts
- Automatic audio playback pause
- Apple Watch integration
- Adjustable sensitivity
- Easy start/stop functionality
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Audiobook & podcast users know that it is almost impossible to find your place once you have fallen asleep and play has continued. SWIS – Sleep when I sleep. Here is what you will love about SWIS for iOS: It is so easy to use. SWIS alerts you that you are falling asleep & if not dismissed will pause audio playback making it easier to find where you left off in a story or podcast. SWIS detects that you are falling asleep & sends you an alert through the watch. We recommend that you stop audio playback when alerted. However, should you feel that you are not falling asleep and dismiss it the App will reset at a less sensitive level and alert you should it again detect sleep. SWIS uses health data from your Apple Watch to determine that you are falling asleep. For accuracy, this data updates throughout the day. Simply open SWIS on your watch when you are listening to audio and press Start. When alerted or when finished press Stop. Apple Watch required. DO NOT RELY ON SWIS TO ALERT YOU THAT YOU MAY BE FALLING ASLEEP WHEN DRIVING. Apple standard Terms of use apply and can be found at https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
CerePlay
Explore a wide range of text-to-speech voices in various languages and accents. Preview and purchase high-quality, human-like voices to enhance your device's linguistic capabilities for productivity or enjoyment.
- Browse text-to-speech voices
- Multiple languages and accents
- Preview voices before purchase
- Human-like voice quality
- Supports iPhone and iPad
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Step into a world of voice diversity with CereProc's innovative app for iPhone & iPad. Whether you're enhancing productivity or simply indulging in the joy of listening, our app offers a seamless browsing experience of text-to-speech voices in a multitude of languages and accents. Preview voices before purchase to ensure they match your expectations and needs perfectly. Embrace the future of voice technology with the introduction of CereProc Version 7 voices, presenting CereWave alternatives that deliver remarkably human-like outputs. Transform your device into a powerhouse of linguistic versatility with CereProc.
Screenshots
Verdict
The clearest difference is review sentiment: CerePlay at 57% against Sleep When I Sleep's 0%. CerePlay also leads on rating (3.8 vs 1.0) and update cadence (every 3 weeks vs every 4 months). Sleep When I Sleep's advantage is iOS requirement (11.1 vs 17.2). On price, ratings volume, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Sleep When I Sleep sells 1 in-app purchase, starting at $5.49 per year and CerePlay sells 34 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
CerePlay holds the better App Store score, 3.8 against 1.0. Both are backed by a comparable volume of ratings — 2 and 4 respectively. Written reviews point the same way: 0% of Sleep When I Sleep's written reviews are positive against 57% of CerePlay's.
Sleep When I Sleep ships an update every 4 months, CerePlay every 3 weeks. The most recent releases landed on October 6, 2026 and October 21, 2026 respectively.
| Parameter | Sleep When I Sleep | CerePlay |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (2 ratings) | 3.8 (4 ratings) — better |
| Positive reviews | 0.0% of reviews | 57.1% of reviews — better |
| Number of ratings | 2 | 4 — better |
| Update frequency | Every 4 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPod, Apple Watch — better | iPhone, iPad |
| Requires iOS | 11.1 — better | 17.2 |
| Further details — not scored | ||
| Size | 35 MB | 90 MB |
| Age rating | 4+ | 4+ |
| Developer | SWIS APP LTD | CereProc Ltd |
Customer experience
Sleep When I Sleep
CerePlay
In-app purchases
Sleep When I Sleep
- 7 Day Free Trial7 Days trial$5.491 Year
CerePlay
- Caitlin TTS$0.99
- Carolyn TTS$0.99
- Giles TTS$0.99
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- Jess TTS$0.99
- Hannah TTS$0.99
- Katherine TTS$0.99
- Isabella TTS$0.99
- Kirsty TTS$0.99
- Lauren TTS$0.99
- Megan TTS$0.99
- Sarah TTS$0.99
- William TTS$0.99
- Stuart TTS$0.99
- Robot TTS$0.99
- Sue TTS$0.99
- Ylva TTS$0.99
- Yuki TTS$0.99
- Suzanne TTS$0.99
- Adam TTS$0.99
- Ben TTS$0.99
- Daria TTS$0.99
- Jack TTS$0.99
- Mairi TTS$0.99
- Ghost TTS$0.99
- Demon TTS$0.99
- Nicole TTS$0.99
- Amy TTS$0.99
- Ana TTS$0.99
- Andy TTS$0.99
- Ceitidh TTS$0.99
- Lily TTS$0.99
- Jordan TTS$0.99
- Sam TTS$0.99
- Nathan TTS$0.99









