OpenTime vs Marklens
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OpenTime
Quickly find your open time slots by analyzing your device calendars. This app offers flexible date range views, slot duration selection, and convenient sharing options without requiring accounts or tracking your data.
- View free/busy slots for any date range
- Slot duration picker with chip subdivision
- Quick sharing of daily availability
- Customizable appearance (light/dark/system)
- Pinned queries for one-tap access
- Home screen widgets and Live Activities
- Apple Watch companion app
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Quickly see when you're free. Open Time reads your device calendars and shows your open time slots. No accounts, no servers, no tracking. FEATURES - View free and busy slots for today, tomorrow, or any date range - Choose which calendars count: exclude holidays, sports schedules, or shared calendars, and every list, widget, and share reflects only the calendars you pick - Slot duration picker (15, 30, or 60 minutes). Chips subdivide your free blocks at the chosen interval - Long-press any chip for Open in Calendar, Create Event Here, or Copy Time - Long-press any day name to Share or Copy that day's availability to anywhere (Messages, Mail, Notes) - Light, dark, or system appearance with an in-app picker - Pull to refresh, and availability refreshes automatically after you create or edit an event - Show or hide busy events - Toggle weekends on or off - This Week, Next Week, and Next 14 Days quick picks - Custom date range picker - Home screen widgets (small and medium). Tap any chip to jump straight to that slot in the app - Live Activities and Dynamic Island for real-time free/busy on your lock screen - Apple Intelligence query bar on supported devices: type "tomorrow afternoon for 30 min" or "any hour Friday afternoon" and get the matching slots - Siri and Shortcuts: try "What's my availability in Open Time" or "When am I free in Open Time" - Apple Watch companion to check your week from your wrist - Share Extension to drop your availability into any app from the share sheet - iMessage app to pick days and send your availability without leaving the conversation PRIVACY FIRST Your calendar data stays on your device. No accounts. No analytics. No third-party servers. Zero data collection. Open Time uses Apple's EventKit to read your calendars locally. Nothing ever leaves your device. Perfect for freelancers, consultants, and anyone who needs to quickly share when they're available.
Marklens
This app is a fast, native Markdown viewer for macOS, iPadOS, and iPhone. It renders .md files instantly with beautiful typography, themes, syntax highlighting, and diagrams. Designed for reading, it offers a private and friction-free experience.
- Instant Markdown rendering
- Syntax highlighting for 30+ languages
- Mermaid diagram support
- GitHub-Flavored Markdown
- Light and dark themes
- Export to PDF
- Quick Look preview on macOS
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Marklens is a fast, native Markdown viewer for macOS, iPadOS, and iPhone. Open any .md file with a click and see it rendered immediately — beautiful typography, light and dark themes, syntax-highlighted code, and Mermaid diagrams. No editor, no library, no friction. HIGHLIGHTS • Instant render — every .md opens in a clean, focused window • 30+ language syntax highlighting via highlight.js, bundled offline • Mermaid 11 diagrams — flowcharts, sequence, state, xy-charts and more • GitHub-Flavored Markdown — tables, task lists, footnotes, strikethrough • Light and dark theme matching the system appearance • Quick Look on macOS — press Space on any .md in Finder for a rendered preview • Export to PDF on every platform • Pinch-to-zoom on iPadOS and iPhone, ⌘+ / ⌘− / ⌘0 on macOS • Open files via drag-and-drop, the Share Sheet, or the Files app MADE FOR READING Marklens doesn't try to be a notes app or a knowledge base. It opens a file, renders it perfectly, and gets out of the way. If you write Markdown in another tool — VS Code, Obsidian, GitHub, your favorite text editor — Marklens is the viewer you reach for to look at the result. PRIVATE BY DESIGN Marklens collects nothing. No analytics, no telemetry, no crash reports, no network requests. Every rendering asset — Mermaid, highlight.js, fonts — ships inside the app. Read the full privacy policy at https://donald-jackson.github.io/marklens/privacy/ OPEN SOURCE Marklens is MIT-licensed and developed in the open. Source, issues, and contribution guide live at https://github.com/donald-jackson/marklens.
Screenshots
Verdict
The clearest difference is price: Marklens at Free against OpenTime's $0.99. Marklens also leads on ratings volume (3 vs 1) and iOS requirement (18.0 vs 26.2). OpenTime's advantage is update cadence (every 2 days vs monthly). On rating, ads, in-app purchases 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
Marklens is free to download; OpenTime costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for OpenTime against 5.0 for Marklens. Both are backed by a comparable volume of ratings — 1 and 3 respectively.
OpenTime ships an update every 2 days, Marklens monthly. Both last shipped on October 24, 2026.
| Parameter | OpenTime | Marklens |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 5.0 (1 ratings) | 5.0 (3 ratings) |
| Positive reviews | — | 0.0% of reviews |
| Number of ratings | 1 | 3 — better |
| Update frequency | Every 2 days — better | Monthly |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, Mac |
| Requires iOS | 26.2 | 18.0 — better |
| Further details — not scored | ||
| Size | 4 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | james tannahill | Donald Jackson |
Customer experience
OpenTime
Marklens
In-app purchases
OpenTime
No in-app purchases
Marklens
No in-app purchases









