# One Calendar vs Telescopic

The clearest difference is ratings volume: One Calendar at 21K against Telescopic's 2. One Calendar also leads on device support (4 vs 1) and iOS requirement (15.0 vs 17.0). Telescopic's advantage is rating (5.0 vs 4.8) and update cadence (weekly vs fortnightly). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. One Calendar sells 1 one-off in-app purchase and Telescopic sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

Telescopic holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: One Calendar has 21K ratings behind it against 2, so its average is the more settled of the two.

One Calendar ships an update fortnightly, Telescopic weekly. The most recent releases landed on October 20, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | One Calendar | Telescopic |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (21K ratings)](https://appshunter.io/ios/app/one-calendar/id1238379385/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/telescopic/id6758728613/reviews)** |
| Number of ratings | **21K** | 2 |
| Positive reviews | 80.7% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | **Weekly** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 89 MB | 12 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [Code Spark](https://appshunter.io/developer/1238379384) | [Acavia](https://appshunter.io/developer/1874623352) |

## 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


### Telescopic

[App page](https://appshunter.io/ios/app/telescopic/id6758728613)

Log and verify predictions from any source, building a verifiable record of accuracy over time. This app automatically checks in and updates scores, offering a private way to track your own and others' foresight.

**Highlights:** Log predictions via voice, text, or URL, Automatic check-ins and outcome verification, Build a verifiable record of accuracy, Private by default, no public profiles, Track your own and others' foresight

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $4.99 | per month |
| Premium Monthly | $9.99 | per month |


## Frequently asked questions

### Is One Calendar free?

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

### Is Telescopic free?

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

### Which has better reviews, One Calendar or Telescopic?

Telescopic is rated higher. One Calendar averages 4.8 out of 5 from 21K ratings, while Telescopic averages 5.0 from 2 ratings.

### Do One Calendar or Telescopic have ads?

Neither One Calendar nor Telescopic shows ads.

### Which is updated more often, One Calendar or Telescopic?

One Calendar ships an update fortnightly, and Telescopic weekly. Most recently, One Calendar was updated on October 20, 2026 and Telescopic on October 9, 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.*