Comparison

DevStack Tools vs hYYa ink

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

DevStack Tools

Features
Read full description

DevStack is the ultimate offline toolbox designed specifically for developers. Stop pasting your sensitive data, JSONs, and JWT tokens into random websites! DevStack brings all your essential daily utilities into one blazing-fast, privacy-first application that works entirely offline. Features include: • Formatters & Minifiers (JSON, XML, SQL, JavaScript) • Encoders & Decoders (Base64, URL, JWT) • Generators (UUID, Hash, QR Code, Lorem Ipsum) • Converters (Number Base, Date & Time) • Text Utilities (Regex Tester) • Design Tools (Color Picker) Boost your productivity and keep your data safe today with DevStack!

About

hYYa ink

This app transforms raw text files like Markdown, JSON, and CSV into readable, editable documents. It also offers robust PDF management, including editing, signing, and making scanned documents searchable. AI integration allows for summarization and reformatting of text-based files.

Highlights
  • Live Markdown rendering with formatting toolbar
  • Editable JSON, YAML, TOML trees
  • Interactive CSV/TSV tables
  • Offline diagram generation (Mermaid, Graphviz)
  • Beautifully typeset LaTeX math
  • PDF editing, signing, and search
  • On-device AI actions for text manipulation
Read full description

Stop reading syntax. Start reading documents. hYYa ink opens the files developers, students and academics work with every day, and turns them into beautiful, readable, editable documents instead of walls of raw text. On Mac, iPhone, iPad and Apple Vision Pro. ONE APP, MANY FORMATS • Markdown — rendered live, with a formatting toolbar (bold, headings, lists, quotes, links) • JSON, YAML, TOML — collapsible trees, with JSON values editable right in the tree • CSV & TSV — a real table, editable cell by cell • Mermaid & Graphviz — diagrams drawn instantly, fully offline • LaTeX — math typeset beautifully • Jupyter notebooks — cells, code and text outputs, cleanly laid out • AsciiDoc, Org-mode, XML, diff, logs — readable at last EDIT, DON'T JUST VIEW Edit the source and watch the document update. On Mac, iPad and Apple Vision Pro, a split view shows source and preview side by side. Change JSON values and CSV cells right in the preview, and hYYa ink writes the file back in valid syntax for you. Start a new document in any format: tap the format label at the top of a document, then choose Graphviz, Mermaid, LaTeX, JSON and more. PDF — READ, SEARCH, ORGANISE, SIGN Open any PDF as a real document. Find any word with a live match count. Browse by page thumbnail or by the document's own contents. Is the file password-protected? hYYa ink asks for the password and opens it. To add text, tap the exact spot on the page and type, then drag the text into place. Draw your signature by hand, then place, resize and rotate it. Mark up a page freehand with pen, pencil and marker, or highlight, underline and strike through the text you select. Make a scanned PDF searchable: text recognition adds a text layer to scanned pages, so you can search them. It runs on your device, and your pages are never sent anywhere. You can also reorganise pages, protect a PDF with a password, compress it or add a watermark. Each of these, like making a PDF searchable, writes a NEW file and leaves the PDF you opened untouched. And you can compare two PDFs to see which pages differ. BRING YOUR OWN AI Use your own key with an AI service: OpenRouter, Groq, Together AI, or another service that works the same way. The AI actions work on every format except PDF: "Explain", "Summarize", "Reformat" and "Fix errors", plus "Make diagram", which writes Mermaid code for a diagram of your document. Your key stays on your device. Only the open document's text is sent, and only when you use an AI action. Every AI result says it was written by AI and names the model. PRIVATE BY DESIGN. BEAUTIFUL BY DESIGN. No accounts. No tracking. No data collection. Documents open and display on your device without an internet connection, and they never leave your device unless you ask. FREE TO READ, PRO TO EDIT Reading and previewing every format hYYa ink opens is free forever, and so are the "Export to PDF" and "Print" commands. On PDFs, search, the page and contents browser, and opening password-protected files are free too. A free 7-day trial unlocks everything. After that, a single one-time purchase unlocks editing and the AI features permanently, on Mac, iPhone, iPad and Apple Vision Pro. On Mac, select a file in Finder and press Space: Quick Look shows CSV and TSV as a table, JSON neatly indented, and Markdown, YAML and other text files as plain, readable text. From hYYa — more than apps. Companions you can trust.

Screenshots

DevStack Tools3 screens
hYYa ink4 screens

Verdict

The call

The clearest difference is in-app purchases: DevStack Tools at none against hYYa ink's 1. DevStack Tools also leads on iOS requirement (13.0 vs 17.0). hYYa ink's advantage is update cadence (every 3 days vs every 6 weeks). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. hYYa ink sells 1 one-off in-app purchase. DevStack Tools asks for nothing beyond the download.

UpkeepUpdate frequency

DevStack Tools ships an update every 6 weeks, hYYa ink every 3 days. The most recent releases landed on October 8, 2026 and October 19, 2026 respectively.

Scorecard3 real differences · 6 level
DevStack Tools versus hYYa ink: the parameters behind the verdict, then further details
ParameterDevStack ToolshYYa ink
PriceFreeFree
Rating—5.0 (1 ratings) — better
Number of ratings—1 — better
Update frequencyEvery 6 weeksEvery 3 days — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Freemium
DevicesiPhone, iPad, iPod, MaciPhone, iPad, Mac, Vision Pro
Requires iOS13.0 — better17.0
Further details — not scored
Size29 MB16 MB
Age rating4+4+
DeveloperMan Sao NgHassaan Abdeen

In-app purchases

None

DevStack Tools

No in-app purchases

1 purchases

hYYa ink

One-time1
  • hYYa ink Pro$19.99

Questions

Is DevStack Tools free?
DevStack Tools is free to download, with no in-app purchases.
Is hYYa ink free?
hYYa ink is free to download, with in-app purchases available.
Do DevStack Tools or hYYa ink have ads?
Neither DevStack Tools nor hYYa ink shows ads.
Which is updated more often, DevStack Tools or hYYa ink?
DevStack Tools ships an update every 6 weeks, and hYYa ink every 3 days. Most recently, DevStack Tools was updated on October 8, 2026 and hYYa ink on October 19, 2026.

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