# Greenbot Hydra vs Calendar

The clearest difference is ads: Greenbot Hydra at none against Calendar's shown. Calendar's advantage is update cadence (every 2 weeks vs every 4 months). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Greenbot Hydra ships an update every 4 months, Calendar every 2 weeks. The most recent releases landed on September 15, 2026 and September 7, 2026 respectively.

## The numbers

| Metric | Greenbot Hydra | Calendar |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 4 months | **Every 2 weeks** |
| Size | 18 MB | 39 MB |
| Requires iOS | **14.0** | 15.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Biobot SAS](https://appshunter.io/developer/1154049256) | [Mahadev Enterprise](https://appshunter.io/developer/1751937034) |

## What reviewers say

### Greenbot Hydra

[App page](https://appshunter.io/ios/app/greenbot-hydra/id6744179052)

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

**In-app purchases:** none


### Calendar

[App page](https://appshunter.io/ios/app/calendar-event-planner/id6753937134)

**In-app purchases:** none


## Frequently asked questions

### Is Greenbot Hydra free?

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

### Is Calendar free?

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

### Do Greenbot Hydra or Calendar have ads?

Calendar shows ads; Greenbot Hydra does not.

### Which is updated more often, Greenbot Hydra or Calendar?

Greenbot Hydra ships an update every 4 months, and Calendar every 2 weeks. Most recently, Greenbot Hydra was updated on September 15, 2026 and Calendar on September 7, 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.*