# CalDown vs Inbox Zero

The clearest difference is ads: CalDown at none against Inbox Zero's shown. CalDown also leads on update cadence (weekly vs every 2 months). Inbox Zero's advantage is iOS requirement (17.0 vs 26.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. CalDown sells 1 one-off in-app purchase and Inbox Zero sells 3 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

CalDown ships an update weekly, Inbox Zero every 2 months. The most recent releases landed on October 30, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | CalDown | Inbox Zero |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/caldown/id6744269741/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | **Weekly** | Every 2 months |
| Monetization | Free | — |
| Size | 13 MB | 30 MB |
| Requires iOS | 26.0 | **17.0** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Valentin Haberling](https://appshunter.io/developer/1803412455) | [Tabish Hassan](https://appshunter.io/developer/1885918100) |

## What reviewers say

### CalDown

[App page](https://appshunter.io/ios/app/caldown/id6744269741)

This app transforms your Apple Calendar into a clear, focused timeline. It highlights your current event with a countdown and remaining time bar, and offers customizable widgets for quick glances on your iPhone, iPad, and Apple Watch. Manage your schedule with enhanced time awareness and notifications.

**Highlights:** Focused event timeline, Countdown and remaining time bar, Customizable widgets, Live Activities on Lock Screen/Dynamic Island, Calendar notifications, Apple Watch complications, Reminders integration (beta)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock CalDown Pro | $9.99 | one-time |


### Inbox Zero

[App page](https://appshunter.io/ios/app/inbox-zero-email-sorter/id6763883599)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| InboxZero Premium | $2.99 | per month |
| InboxZero Premium Yearly | $29.99 | per year |
| Premium Lifetime | $99.99 | one-time |


## Frequently asked questions

### Is CalDown free?

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

### Is Inbox Zero free?

Inbox Zero is free to download, with in-app purchases available.

### Do CalDown or Inbox Zero have ads?

Inbox Zero shows ads; CalDown does not.

### Which is updated more often, CalDown or Inbox Zero?

CalDown ships an update weekly, and Inbox Zero every 2 months. Most recently, CalDown was updated on October 30, 2026 and Inbox Zero on October 25, 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.*