# O2 Calendar vs Shift Planner RosterShift

The clearest difference is in-app purchases: O2 Calendar at none against Shift Planner RosterShift's 3. O2 Calendar also leads on device support (3 vs 1) and iOS requirement (9.0 vs 18.4). Shift Planner RosterShift's advantage is update cadence (daily vs every 4 days). On price and ads there is nothing between them.

Both are free to download. Shift Planner RosterShift sells 3 in-app purchases, starting at $3.99 per month. O2 Calendar asks for nothing beyond the download.

O2 Calendar ships an update every 4 days, Shift Planner RosterShift daily. The most recent releases landed on October 15, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | O2 Calendar | Shift Planner RosterShift |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 days | **Daily** |
| Monetization | Free | — |
| Size | 52 MB | 17 MB |
| Requires iOS | **9.0** | 18.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [O2 VN Tech.,JSC](https://appshunter.io/developer/1547745523) | [EGEMEN KAR](https://appshunter.io/developer/1821858444) |

## What reviewers say

### O2 Calendar

[App page](https://appshunter.io/ios/app/o2-calendar/id1547745521)

Manage your schedule with this app, offering tools for events, appointments, notes, and daily tasks. Set custom reminders for your important activities and organize your day effectively.

**Highlights:** Event creation and management, Customizable event reminders, Daily task reminders, Note-taking functionality, Appointment scheduling

**Features:** macOS Compatibility

**In-app purchases:** none


### Shift Planner RosterShift

[App page](https://appshunter.io/ios/app/shift-planner-rostershift/id6759160894)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| RosterShift Pro Monthly | $3.99 | per month |
| RosterShift Pro (Founders) | $9.99 | per year |
| RosterShift Pro Yearly | $29.99 | per year |


## Frequently asked questions

### Is O2 Calendar free?

O2 Calendar is free to download, with no in-app purchases.

### Is Shift Planner RosterShift free?

Shift Planner RosterShift is free to download, with in-app purchases available.

### Do O2 Calendar or Shift Planner RosterShift have ads?

Neither O2 Calendar nor Shift Planner RosterShift shows ads.

### Which is updated more often, O2 Calendar or Shift Planner RosterShift?

O2 Calendar ships an update every 4 days, and Shift Planner RosterShift daily. Most recently, O2 Calendar was updated on October 15, 2026 and Shift Planner RosterShift on October 25, 2026.

---

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