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Letter Opener vs Folder Preview Pro

Side-by-side comparison for macOS

Letter Opener

8.0
Developer Tools

Display winmail.dat files directly in Mail.app

Folder Preview Pro

8.0
Utilities

Quick Look extension for folders

Metric Letter Opener Folder Preview Pro
Category Developer Tools Utilities
AI Score 8.0 8.0
30-day Installs 5 128
90-day Installs 21 251
365-day Installs 76 625
Version 16.0.7 2.10
Auto-updates No Yes
Deprecated No No
GitHub Stars 3.8K 1
GitHub Forks 241 -
Open Issues 5 -
License MIT
Language Ruby
Last GitHub Commit 1y ago 3mo ago
First Seen Nov 3, 2021 Sep 22, 2025

Reviews

Letter Opener

Letter Opener is a macOS app that simplifies viewing winmail.dat files directly in Mail.app, a common issue for users dealing with Outlook-generated emails. It offers developers a tool to preview emails in the browser, enhancing workflow efficiency.

Displays winmail.dat files within Mail.app, allowing users to view rich text and embedded content without extra software.

Pros

  • + Effectively handles winmail.dat files, a common issue
  • + Actively maintained with a robust community following
  • + Open-source MIT license, appealing to developers

Cons

  • - Low recent installs indicate limited awareness or adoption
  • - Manual updates required, no auto-update feature

Folder Preview Pro

Folder Preview Pro enhances macOS by enabling Quick Look previews for folders, displaying contents with actions and thumbnails. Ideal for users managing files frequently, it offers a seamless way to preview and interact with folders directly from Finder.

Enables Quick Look previews for folders, showing contents with actions and thumbnails.

Pros

  • + Quick folder preview functionality
  • + Actions and thumbnails for enhanced interaction
  • + Auto-update feature for seamless updates
  • + One-time purchase model with lifetime updates

Cons

  • - Limited GitHub activity and transparency
  • - Unknown license and development language