# SleepMi vs Letterly

The clearest difference is in-app purchases: SleepMi at none against Letterly's 9. SleepMi also leads on iOS requirement (9.0 vs 16.0). Letterly's advantage is update cadence (every 10 days vs every 3 months) and review sentiment (78% vs 50%). On price and ads there is nothing between them.

Both are free to download. Letterly sells 9 in-app purchases, starting at $19.99 per month. SleepMi asks for nothing beyond the download.

SleepMi ships an update every 3 months, Letterly every 10 days. The most recent releases landed on October 6, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | SleepMi | Letterly |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.7 (1.1K ratings)](https://appshunter.io/ios/app/letterly-ai-note-taker/id6464049772/reviews)** |
| Number of ratings | — | **1.1K** |
| Positive reviews | 50.0% of reviews | **78.1% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 10 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 11 MB | 95 MB |
| Requires iOS | **9.0** | 16.0 |
| Devices | iPhone, iPod | **iPhone, iPad, Mac, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Shenzhen LINGXI Technology Co., Ltd](https://appshunter.io/developer/957619029) | [Anton Lebedev](https://appshunter.io/developer/1763234652) |

## What reviewers say

### SleepMi

[App page](https://appshunter.io/ios/app/sleepmi/id6443874901)

This app focuses on improving sleep quality through intelligent wearable devices and comprehensive data analysis. It aims to leverage technology for a better sleep experience.

**Highlights:** Intelligent wearable device integration, Comprehensive sleep data showcasing, Technology-driven sleep enhancement, Improved user experience for sleep, Deep software integration

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Letterly

[App page](https://appshunter.io/ios/app/letterly-ai-note-taker/id6464049772)

Instantly transform your speech into polished text for notes, messages, social media, and more. Organize with custom tags, use offline, and choose from over 25 rewrite styles. Supports over 90 languages and syncs across all your devices.

**Highlights:** Speech to text transcription, Customizable text rewriting, Note organization with tags, Offline recording, Multi-language support, Cross-device syncing, Audio file upload transcription

**Features:** Apple Watch app

**In-app purchases (9)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PRO Subscription (1 month) | $19.99 | per month |
| PRO Subscription (3 months) | $44.90 | per 3 months |
| PRO Subscription (1 Year) | $69.99 | per year |
| PRO Subscription (1 Year) | $79.99 | per year |
| PRO Subscription (1 Year) | $89.99 | per year |
| PRO Subscription (12 months) | $99.99 | per year |
| PRO Subscription (12 months) | $99.99 | per year |
| PRO Subscription (Lifetime) | $199.99 | one-time |
| PRO Subscription (Lifetime) | $249.99 | one-time |

**What reviewers like**

- 🚀 Quick, easy, and consistent
- 👍 Fantastic application
- 👍 Game-changing app
- 👍 Admissions
- 👍 My go-to app

**What reviewers complain about**

- 🐛 Hopeless info and double charged
- 🐛 A scam
- 🐛 Big Promise, Big Fizzle
- 🐛 NO! NO! NO!
- 🐛 Formatting

**Reported bugs**

- Login screen freezes
- Incompatible with older devices
- When I get phone calls, I lose the entire recording

**Requested features**

- Dark mode option
- Advanced analytics dashboard
- Ability to use the artificial intelligence to search through all of my old notes for similar topics or keywords


## Frequently asked questions

### Is SleepMi free?

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

### Is Letterly free?

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

### Do SleepMi or Letterly have ads?

Neither SleepMi nor Letterly shows ads.

### Which is updated more often, SleepMi or Letterly?

SleepMi ships an update every 3 months, and Letterly every 10 days. Most recently, SleepMi was updated on October 6, 2026 and Letterly on October 27, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*