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