# Calca vs Obsidian

The clearest difference is price: Obsidian at Free against Calca's $9.99. Obsidian also leads on in-app purchases (none vs 2) and update cadence (every 3 weeks vs every 5 months). Calca's advantage is review sentiment (76% vs 62%). On rating, ads, device support and iOS requirement there is nothing between them.

Obsidian is free to download; Calca costs $9.99 up front. Calca sells 2 one-off in-app purchases. Obsidian asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.5 for Calca against 4.5 for Obsidian. That said, the two scores are not equally well evidenced: Obsidian has 2.7K ratings behind it against 153, so its average is the more settled of the two. Written reviews are what separate them: 76% of Calca's written reviews are positive against 62% of Obsidian's.

Calca ships an update every 5 months, Obsidian every 3 weeks. The most recent releases landed on September 25, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | Calca | Obsidian |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [4.5 (153 ratings)](https://appshunter.io/ios/app/calca/id635757879/reviews) | [4.5 (2.7K ratings)](https://appshunter.io/ios/app/obsidian-connected-notes/id1557175442/reviews) |
| Number of ratings | 153 | **2.7K** |
| Positive reviews | **76.5% of reviews** | 62.1% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 3 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Best chart rank | — | **#133** |
| Size | 78 MB | 38 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Krueger Systems, Inc.](https://appshunter.io/developer/299293363) | [Dynalist Inc.](https://appshunter.io/developer/1195392807) |

## What reviewers say

### Calca

[App page](https://appshunter.io/ios/app/calca/id635757879)

This app is an advanced symbolic calculator and text editor. It solves equations, simplifies expressions, and allows you to explain your work alongside calculations. Calculations update instantly as you type, and all data is stored as plain text for easy sharing and device syncing.

**Highlights:** Symbolic calculation, Equation solving, Expression simplification, Markdown text editor, Real-time updates, Unit and currency conversion, Matrix operations

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 6-Month Optional Patronage | $4.99 | one-time |
| 12-Month Optional Patronage | $7.99 | one-time |

**What reviewers like**

- 💡 Unique blend of text editor and calculator
- 📝 Markdown support for documentation
- 🔄 Dynamic recalculation of all values
- ⚙️ Powerful mathematical and algebraic capabilities
- 📊 Unit conversion and unit-aware calculations

**What reviewers complain about**

- 🐛 Magic Keyboard input bugs on iPad
- ⚠️ Appears abandoned or poorly maintained
- 🐛 Text selection issues with external keyboards
- 📱 iPad landscape mode problems
- 🐛 Cursor jumping and screen jumping during editing

**Reported bugs**

- Magic Keyboard causes number input to overwrite instead of append
- Text selection before numbers triggers increment/decrement instead of selecting
- Cursor jumps forward and backward with external keyboards
- iPad Pro keyboard truncation in portrait mode
- Arrow key (=>) doesn't work in landscape mode

**Requested features**

- Files app and document browser integration
- Dropbox and Google Drive support
- Date calculation functionality
- Looping and iteration support
- User-defined function storage in separate files


### Obsidian

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

**Currently charting:** #133 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


## Frequently asked questions

### Is Calca free?

Calca costs $9.99, and also offers in-app purchases.

### Is Obsidian free?

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

### Which has better reviews, Calca or Obsidian?

Calca and Obsidian are both rated 4.5 out of 5 on the App Store, from 153 and 2.7K ratings respectively.

### Do Calca or Obsidian have ads?

Neither Calca nor Obsidian shows ads.

### Which is updated more often, Calca or Obsidian?

Calca ships an update every 5 months, and Obsidian every 3 weeks. Most recently, Calca was updated on September 25, 2026 and Obsidian on September 24, 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.*