# One Calendar vs Brainstorm Master

The clearest difference is in-app purchases: Brainstorm Master at none against One Calendar's 1. One Calendar's advantage is device support (4 vs 2) and iOS requirement (15.0 vs 18.0). On price and ads there is nothing between them.

Both are free to download. One Calendar sells 1 one-off in-app purchase. Brainstorm Master asks for nothing beyond the download.

## The numbers

| Metric | One Calendar | Brainstorm Master |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (21K ratings)](https://appshunter.io/ios/app/one-calendar/id1238379385/reviews)** | — |
| Number of ratings | **21K** | — |
| Positive reviews | 80.7% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Fortnightly | — |
| Monetization | Free with in-app purchases | — |
| Size | 89 MB | 10 MB |
| Requires iOS | **15.0** | 18.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Code Spark](https://appshunter.io/developer/1238379384) | [Ian SMITH](https://appshunter.io/developer/1877217033) |

## What reviewers say

### One Calendar

[App page](https://appshunter.io/ios/app/one-calendar/id1238379385)

Consolidate all your digital calendars into a single, easy-to-read view. Manage appointments, events, and birthdays from various providers like Google, Outlook, iCloud, and more, all within one application.

**Highlights:** Integrates multiple calendar providers, Easy-to-read overview, Manage appointments and events, View birthdays, Cross-platform availability

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OneCalendar premium | $5.99 | one-time |

**What reviewers like**

- 🚀 Easy to use
- 👍 Clean and simple interface
- 👍 Integrates multiple calendars
- 🚀 Syncs across devices
- 👍 Customizable colors and themes

**What reviewers complain about**

- 🐛 Syncing issues
- 🐛 Bugs and glitches
- 🔒 Lacks security features
- 🔋 Drains battery
- 👎 Restrictive features in free version

**Reported bugs**

- Sync errors
- Unresponsive buttons
- Incorrect time zone display
- Duplicate events
- Inability to delete future occurrences of recurring events

**Requested features**

- Multiple reminders for events
- Ability to edit recurring events
- Option to change event calendar after creation
- Printing support
- More customization options


### Brainstorm Master

[App page](https://appshunter.io/ios/app/brainstorm-master/id6761441700)

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

**In-app purchases:** none


## Frequently asked questions

### Is One Calendar free?

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

### Is Brainstorm Master free?

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

### Do One Calendar or Brainstorm Master have ads?

Neither One Calendar nor Brainstorm Master shows ads.

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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.*