Comparison

HEY Calendar vs HTML Previewer

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

Head to head
About

HEY Calendar

This calendar app organizes your schedule around days and weeks, reflecting how people naturally think. It supports habits, highlights important events, and accommodates flexible scheduling for tasks that don't have a fixed time. Enjoy a full-featured experience with unique twists on conventional calendar functions.

Highlights
  • Weekly view focus
  • Habit tracking
  • Event highlighting
  • Flexible scheduling for 'maybe' tasks
  • Event countdowns
  • Day labels for context
  • Color-coded sub-calendars
  • Flexible reminders
Read full description

Make your day. The all-new HEY Calendar puts time on your side. Week after week, not month after month People think in days and weeks, not months. What’s tomorrow? Later this week? Next week? The HEY Calendar is built around how you think, not how paper calendars were designed. Habits and highlights Establish a habit, stick with it. Circle important events so they stand out. Fill your days with memories or moments — not just events. “Sometime this week” mimics real life Need to get an oil change? Get some cash from the ATM? Write a thank you note? Maybe this week or next, just not exactly sure when you’ll have a chance? HEY knows “maybe” is a real thing. And plenty more The HEY Calendar is a full-featured calendar with many original twists on common — and not so common — conventions. Soon you’ll wonder why all calendars don’t work like this. - Set countdowns for anticipated events - Use Day Labels to add context to days - Set up color-coded sub-calendars - Flexible reminders so you don’t miss out

About

HTML Previewer

Read full description

Open received HTML and ZIP reports, read Markdown notes, and inspect JSON or YAML on iPhone and iPad. Files are processed on your device. Read the content, keep the formatting - View HTML layouts, graphics, and animations. - Read Markdown tables and highlighted code, with one-tap code copying. - Display Markdown math equations and Mermaid diagrams offline. - Browse HTML and Markdown pages inside ZIP reports with local CSS and image assets. - Search within HTML and Markdown, navigate headings, adjust reading appearance, and reopen at your saved reading position. Inspect JSON and YAML - Expand nested objects and arrays, search fields and values, and check highlighted source with line numbers. - Copy values or field paths and jump to the corresponding source line. - View and copy large JSON numeric IDs without rounding their digits. - Locate syntax errors by line and column. YAML also supports multiple documents. Import, organize, and share - Open files from Files, Mail, AirDrop, messaging apps, cloud drives, or other apps. Open/share menu availability depends on iOS and the source app. - Select multiple documents or ZIP packages. Update duplicates, keep both copies, or skip individual files, then review import results. - Paste HTML, Markdown, JSON, or YAML text to create a local preview. - Find saved files by filename, pin frequent documents, and rename display titles. - Share original files or complete ZIP packages. Export HTML and Markdown previews as PDF. - Try the built-in HTML, Markdown, JSON, YAML, and ZIP samples. Supported extensions: .html, .htm, .md, .markdown, .json, .yaml, .yml, and .zip. JSON and YAML previews are read-only and share the original file. JSONC comments and trailing commas are not supported. PDF export is available for HTML and Markdown. Privacy and purchase Files are processed on device; the app does not upload your files. No account or ads. Paid download with no subscription or in-app purchase. New HTML files, including HTML inside ZIP packages, open in Interactive mode with page JavaScript and external resources enabled. The HTML content can make network requests. Select Safe Preview to block page scripts and external HTTP/HTTPS resources. External navigation and form navigation remain blocked in both modes. Saved preview choices are preserved when reopening files.

Screenshots

HEY Calendar4 screens
HTML Previewer4 screens

Verdict

The call

The clearest difference is price: HEY Calendar at Free against HTML Previewer's $5.99. HTML Previewer's advantage is update cadence (every 4 days vs fortnightly) and chart position (#176 vs unranked). On ads, in-app purchases, device support and iOS requirement 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

HEY Calendar is free to download; HTML Previewer costs $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

HEY Calendar ships an update fortnightly, HTML Previewer every 4 days. The most recent releases landed on October 14, 2026 and October 11, 2026 respectively.

Scorecard3 real differences · 8 level
HEY Calendar versus HTML Previewer: the parameters behind the verdict, then further details
ParameterHEY CalendarHTML Previewer
PriceFree — better$5.99
Rating4.7 (655 ratings) — better—
Positive reviews56.4% of reviews—
Number of ratings655 — better—
Update frequencyFortnightlyEvery 4 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
Best chart rank—#176 — better
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.217.0 — better
Further details — not scored
Size64 MB9 MB
Age rating4+4+
Developer37Signals LLCSHIFENG ZHANG

Bugs and requests

HEY Calendar

Reported bugs

4 issues
  • Events not showing up on calendar
  • Notifications not working as expected
  • Frequent crashes and performance issues
  • Inability to edit events from external calendars

Requested features

5 requests
  • Two-way sync with other calendar services
  • Ability to set custom recurrence patterns
  • Integration with mapping/navigation apps
  • Family/shared calendar support
  • Calendar widget for quick access

HTML Previewer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

HEY Calendar

No in-app purchases

None

HTML Previewer

No in-app purchases

Questions

Is HEY Calendar free?
HEY Calendar is free to download, with no in-app purchases.
Is HTML Previewer free?
HTML Previewer costs $5.99, with no in-app purchases.
Do HEY Calendar or HTML Previewer have ads?
Neither HEY Calendar nor HTML Previewer shows ads.
Which is updated more often, HEY Calendar or HTML Previewer?
HEY Calendar ships an update fortnightly, and HTML Previewer every 4 days. Most recently, HEY Calendar was updated on October 14, 2026 and HTML Previewer on October 11, 2026.

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