# JDK vs Cephalo

The clearest difference is in-app purchases: JDK at none against Cephalo's 2. JDK also leads on device support (3 vs 1) and iOS requirement (15.0 vs 17.6). Cephalo's advantage is ads (none vs shown) and update cadence (every 2 weeks vs every 13 months). On price there is nothing between them.

Both are free to download. Cephalo sells 2 in-app purchases, starting at $2.99 per month. JDK asks for nothing beyond the download.

JDK ships an update every 13 months, Cephalo every 2 weeks. The most recent releases landed on October 27, 2026 and September 29, 2026 respectively.

## The numbers

| Metric | JDK | Cephalo |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 13 months | **Every 2 weeks** |
| Size | 59 MB | 13 MB |
| Requires iOS | **15.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 17+ | 12+ |
| Developer | [OVERCLOUDS SRL](https://appshunter.io/developer/1851998468) | [Iterica B.V.](https://appshunter.io/developer/1832191465) |

## What reviewers say

### JDK

[App page](https://appshunter.io/ios/app/jdk/id1641306987)

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

**In-app purchases:** none


### Cephalo

[App page](https://appshunter.io/ios/app/cephalo-headache-diary/id6749801188)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Cephalo Plus Monthly | $2.99 | per month |
| Cephalo Plus Yearly | $24.99 | per year |


## Frequently asked questions

### Is JDK free?

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

### Is Cephalo free?

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

### Do JDK or Cephalo have ads?

JDK shows ads; Cephalo does not.

### Which is updated more often, JDK or Cephalo?

JDK ships an update every 13 months, and Cephalo every 2 weeks. Most recently, JDK was updated on October 27, 2026 and Cephalo on September 29, 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.*