# Obsidian vs Dev Calc

The clearest difference is rating: Obsidian at 4.5 against Dev Calc's 2.0. Obsidian also leads on in-app purchases (none vs 1) and ads (none vs shown). Dev Calc's advantage is iOS requirement (13.0 vs 15.6). On price, review sentiment and device support there is nothing between them.

Both are free to download. Dev Calc sells 1 in-app purchase, starting at $1.99 per month. Obsidian asks for nothing beyond the download.

Obsidian holds the better App Store score, 4.5 against 2.0. That said, the two scores are not equally well evidenced: Obsidian has 2.7K ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 62% of Obsidian's written reviews are positive against 60% of Dev Calc's.

Obsidian ships an update every 3 weeks, Dev Calc every 2 months. The most recent releases landed on September 24, 2026 and June 4, 2026 respectively.

## The numbers

| Metric | Obsidian | Dev Calc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (2.7K ratings)](https://appshunter.io/ios/app/obsidian-connected-notes/id1557175442/reviews)** | [2.0 (2 ratings)](https://appshunter.io/ios/app/dev-calc-developer-calculator/id1576503219/reviews) |
| Number of ratings | **2.7K** | 2 |
| Positive reviews | **62.1% of reviews** | 60.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 3 weeks** | Every 2 months |
| Monetization | **Free** | Free with in-app purchases |
| Best chart rank | **#136** | — |
| Size | 38 MB | 51 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Dynalist Inc.](https://appshunter.io/developer/1195392807) | [Toshiya Hondo](https://appshunter.io/developer/1571875732) |

## What reviewers say

### Obsidian

[App page](https://appshunter.io/ios/app/obsidian-connected-notes/id1557175442)

**Currently charting:** #136 Top Free · Productivity (US App Store)

Organize your thoughts and ideas with a powerful knowledge base that utilizes local Markdown files. This app acts as your personal second brain, accessible on your mobile device for seamless note-taking and idea connection.

**Highlights:** Local Markdown file storage, Customizable toolbar, Graph view for connections, Community plugins, Themes, iCloud sync

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 🚀 Powerful features
- 👍 Customizable and flexible
- 🔒 Secure and private
- 💡 Innovative note-taking approach
- 🚀 Smooth mobile experience

**What reviewers complain about**

- 🐛 Sync issues and unreliable iCloud integration
- 🔋 Slow startup and performance issues on mobile
- 👎 Steep learning curve for new users
- 👎 Limited sorting and organization options
- 👎 Lack of WYSIWYG editing on mobile

**Reported bugs**

- Sync issues leading to data loss
- Freezing and crashing on mobile devices
- Editing bugs and text input issues

**Requested features**

- Improved sorting and organization options
- WYSIWYG editing on mobile
- Better integration with other cloud storage services
- More intuitive onboarding process for new users
- Native mobile widgets and share sheet integration


### Dev Calc

[App page](https://appshunter.io/ios/app/dev-calc-developer-calculator/id1576503219)

This app assists developers and programmers with immediate numeric conversions between binary, octal, decimal, and hexadecimal formats. It also provides tools for generating color codes from RGB, HSL, and HSV values, with a color picker and preset options.

**Highlights:** Numeric conversion (Bin, Oct, Dec, Hex), Signed/Unsigned options, Adjustable bit sizes (8, 16, 32, 64), RGB, HSL, HSV color code generation, Color picker, Preset color options

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads (Monthly) | $1.99 | per month |


## Frequently asked questions

### Is Obsidian free?

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

### Is Dev Calc free?

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

### Which has better reviews, Obsidian or Dev Calc?

Obsidian is rated higher. Obsidian averages 4.5 out of 5 from 2.7K ratings, while Dev Calc averages 2.0 from 2 ratings.

### Do Obsidian or Dev Calc have ads?

Dev Calc shows ads; Obsidian does not.

### Which is updated more often, Obsidian or Dev Calc?

Obsidian ships an update every 3 weeks, and Dev Calc every 2 months. Most recently, Obsidian was updated on September 24, 2026 and Dev Calc on June 4, 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.*