# Simple Sequence Diagram AI vs hYYa ink

The clearest difference is update cadence: hYYa ink at every 2 days against Simple Sequence Diagram AI's every 2 weeks. Simple Sequence Diagram AI's advantage is iOS requirement (15.6 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Simple Sequence Diagram AI sells 2 in-app purchases, starting at $4.99 per month and hYYa ink sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Simple Sequence Diagram AI ships an update every 2 weeks, hYYa ink every 2 days. The most recent releases landed on November 8, 2026 and November 11, 2026 respectively.

## The numbers

| Metric | Simple Sequence Diagram AI | hYYa ink |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/hyya-ink-markdown-and-json/id6786209046/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 2 days** |
| Monetization | — | Freemium |
| Size | 55 MB | 18 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | iPhone, iPad, iPod, Mac | iPhone, iPad, Mac, Vision Pro |
| Age rating | 4+ | 4+ |
| Developer | [YUKI TANAIKE](https://appshunter.io/developer/478558546) | [Hassaan Abdeen](https://appshunter.io/developer/1866789892) |

## What reviewers say

### Simple Sequence Diagram AI

[App page](https://appshunter.io/ios/app/simple-sequence-diagram-ai/id6711357061)

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Simple Sequence Flow Pro (Monthly) | $4.99 | per month |
| Simple Sequence Flow Pro (Annual) | $44.99 | per year |


### hYYa ink

[App page](https://appshunter.io/ios/app/hyya-ink-markdown-and-json/id6786209046)

This app transforms raw text files and documents into easily readable formats. It allows for in-document editing, PDF manipulation, format conversion, and AI-powered assistance, all while prioritizing user privacy and offline functionality.

**Highlights:** Read Markdown, JSON, YAML, CSV, diagrams, and more, Edit text files and tables directly, Sign, mark up, and redact PDFs, Convert between various document formats, AI-powered document explanation and summarization, Offline document viewing and editing

**Features:** iPhone Duo support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 7-day Trial | Free | one-time |
| hYYa ink Pro | $19.99 | one-time |


## Frequently asked questions

### Is Simple Sequence Diagram AI free?

Simple Sequence Diagram AI is free to download, with in-app purchases available.

### Is hYYa ink free?

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

### Do Simple Sequence Diagram AI or hYYa ink have ads?

Neither Simple Sequence Diagram AI nor hYYa ink shows ads.

### Which is updated more often, Simple Sequence Diagram AI or hYYa ink?

Simple Sequence Diagram AI ships an update every 2 weeks, and hYYa ink every 2 days. Most recently, Simple Sequence Diagram AI was updated on November 8, 2026 and hYYa ink on November 11, 2026.

---

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