# Daily Diary with Lock vs Theo

The clearest difference is review sentiment: Daily Diary with Lock at 86% against Theo's 0%. Daily Diary with Lock also leads on ads (none vs shown) and rating (4.6 vs 4.2). On price, update cadence, in-app purchases and monetization model there is nothing between them.

Both are free to download. Daily Diary with Lock sells 7 in-app purchases, starting at $2.49 per 7 days and Theo sells 9 in-app purchases, starting at $4.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Daily Diary with Lock holds the better App Store score, 4.6 against 4.2. Both are backed by a comparable volume of ratings — 62 and 16 respectively. Written reviews point the same way: 86% of Daily Diary with Lock's written reviews are positive against 0% of Theo's.

Daily Diary with Lock ships an update monthly, Theo every 2 weeks. The most recent releases landed on October 22, 2026 and October 20, 2026 respectively.

## The numbers

| Metric | Daily Diary with Lock | Theo |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (62 ratings)](https://appshunter.io/ios/app/daily-diary-with-lock-turtle/id1569737377/reviews)** | [4.2 (16 ratings)](https://appshunter.io/ios/app/theo-stop-overthinking/id6759104892/reviews) |
| Number of ratings | **62** | 16 |
| Positive reviews | **85.7% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | Monthly | **Every 2 weeks** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 24 MB | 42 MB |
| Requires iOS | **14.0** | 16.6 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 9+ |
| Developer | [Saturday Technologies, Inc](https://appshunter.io/developer/1242436346) | [Kilby Labs Inc.](https://appshunter.io/developer/6778542781) |

## What reviewers say

### Daily Diary with Lock

[App page](https://appshunter.io/ios/app/daily-diary-with-lock-turtle/id1569737377)

This app provides a private space for journaling, allowing users to write, draw, record voice notes, and add photos or videos. It includes features like soundscapes for relaxation, personalized reminders, and robust security options like Face ID or passcode locks.

**Highlights:** Rich text editor, Sketchpad with precision tools, Add photos and videos, Record voice notes, Customizable soundscapes, Personalized reminders, Face ID/passcode lock

**Features:** macOS Compatibility, Family Sharing, iMessage stickers, Vision Pro support

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly | $2.49 | per 7 days |
| Monthly - Turtle Premium | $5.99 | per month |
| Annual - Turtle Premium | $24.99 | per year |
| Annual | $39.99 | per year |
| Annual | $39.99 | per year |
| Annual | $49.99 | per year |
| Lifetime - Turtle Premium | $49.99 | one-time |

**What reviewers like**

- 👍 Great for journaling and venting
- 👍 Helps organize life, especially for ADHD
- 👍 Useful for tracking journeys (weight loss, medical info)
- 👍 Provides privacy for thoughts
- 👍 Easy to use and accessible

**What reviewers complain about**

- 💰 Premium required for many features (photos, audio, multiple journals)
- 🔒 Privacy features (locking) can be buggy or require payment
- 💸 High cost for premium features ($40/year mentioned)
- 😔 Limited free functionality
- 🐢 Slow performance reported

**Reported bugs**

- Locking feature not working correctly
- App is slow
- Cannot make new pages
- Cannot see typing when reaching bottom of screen
- Formatted text not displaying properly when viewing entries (but displays when editing)

**Requested features**

- Add lines for stylus writing
- Add calendars
- Allow adding photos without premium
- Improve voice diary attachment functionality (stops when screen off)
- Allow listening to voice recordings when screen is off


### Theo

[App page](https://appshunter.io/ios/app/theo-stop-overthinking/id6759104892)

This app helps you stop overthinking by guiding you through a structured analysis of your worries and decisions. It uses evidence-based reasoning to show you the actual probabilities of your concerns, replacing feelings with clarity.

**Highlights:** Structured journaling for worries, Evidence-based probability analysis, Interactive what-if sliders, Sensitivity analysis of evidence, Private thinking journal, Bayesian reasoning framework

**In-app purchases (9)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Theo Plus - Weekly Subscription | $4.99 | per 7 days |
| Theo Plus - Monthly Subscription | $9.99 | per month |
| Theo Plus - 3 Month Subscription | $12.99 | per 3 months |
| Theo Plus - Semiannual Subscription | $39.99 | per 6 months |
| Theo Plus - Annual Subscription | $39.99 | per year |
| Theo Plus - Semiannual Subscription | $39.99 | per 6 months |
| Theo Plus - Semiannual Subscription | $59.99 | per 6 months |
| Theo Plus - Annual Subscription | $69.99 | per year |
| Theo Plus - Annual Subscription | $99.99 | per year |


## Frequently asked questions

### Is Daily Diary with Lock free?

Daily Diary with Lock is free to download, with in-app purchases available.

### Is Theo free?

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

### Which has better reviews, Daily Diary with Lock or Theo?

Daily Diary with Lock is rated higher. Daily Diary with Lock averages 4.6 out of 5 from 62 ratings, while Theo averages 4.2 from 16 ratings.

### Do Daily Diary with Lock or Theo have ads?

Theo shows ads; Daily Diary with Lock does not.

### Which is updated more often, Daily Diary with Lock or Theo?

Daily Diary with Lock ships an update monthly, and Theo every 2 weeks. Most recently, Daily Diary with Lock was updated on October 22, 2026 and Theo on October 20, 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.*