Hyday MD

Hyday MD is a Markdown tool built for reading.

Originally designed as the mobile reader for the Hyday note-taking app, it lets you comfortably read notes stored in iCloud Drive on your iPhone and iPad. It is also a general-purpose lightweight Markdown reader — any .md file written with other tools displays just fine.

DESIGN PRINCIPLES
• Hands off your syntax — your files stay untouched
• Content first — the UI stays quietly in the background
• Typography is the design — hierarchy through type and whitespace, not decoration

FEATURES
• Frontmatter parsing: title, type, tags, createdAt, and lastModified extracted and displayed automatically
• Wiki links: [[note name]] jumps straight to the linked note; the back button returns to the previous one
• Mermaid diagrams: flowcharts, sequence diagrams, and more rendered inline, with full-screen viewing
• Reading font size: four levels (S / M / L / XL), independent of the system setting
• Edit and write back: tap edit, make changes, save — lastModified updates in your local time zone
• LaTeX math: inline and block syntax both supported
• Code blocks: syntax highlighting, language labels, one-tap copy
• Tables: GFM alignment syntax supported
• Task lists: GFM checkboxes rendered in brand colors
• Local images: paths resolved relative to the .md file
• hyday-asset custom scheme: maps to the assets/ folder at the vault root
• Hyday life log marks: start, end, now, idea, important — five states told apart by color
• Subfolder browsing: only folders containing Markdown are shown, keeping lists clean
• Recent files: jump back to your last-read note straight from the home screen
• Recent folders: persisted with iOS security-scoped bookmarks — no re-picking after relaunch
• Bundled fonts: Fira Sans Condensed and Fira Code, fully rendered even offline

PRIVACY
• No user data collected
• No analytics, no tracking
• No network requests (unless your files reference web images)
• Recent files and folders lists live only on your device

GOOD FOR
• Writers, engineers, and researchers who keep Markdown notes
• Hyday note app users
• Anyone who reads technical docs, lecture notes, or study notes on their phone

NOT FOR
• Rich-text (WYSIWYG) editing
• Team collaboration or cloud version control
• Reading PDF, Word, or other formats