HEY Calendar vs HTML Previewer
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Weekly view focus
- Habit tracking
- Event highlighting
- Flexible scheduling for 'maybe' tasks
- Event countdowns
- Day labels for context
- Color-coded sub-calendars
- Flexible reminders
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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
HTML Previewer
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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
Verdict
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
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.
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.
| Parameter | HEY Calendar | HTML Previewer |
|---|---|---|
| Price | Free — better | $5.99 |
| Rating | 4.7 (655 ratings) — better | — |
| Positive reviews | 56.4% of reviews | — |
| Number of ratings | 655 — better | — |
| Update frequency | Fortnightly | Every 4 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Best chart rank | — | #176 — better |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.2 | 17.0 — better |
| Further details — not scored | ||
| Size | 64 MB | 9 MB |
| Age rating | 4+ | 4+ |
| Developer | 37Signals LLC | SHIFENG 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
HEY Calendar
No in-app purchases
HTML Previewer
No in-app purchases









