以下是Firefox 21 beta for Android changelog:

• NEW: Shipping Open Sans and Charis fonts for Web Content.
• NEW: Ability to save media files on long tap.
• CHANGED: Polished UI based on Holo theme.
• CHANGED: CSS -moz-user-select:none selection changed to improve compatibility with -webkit-user-select:none (bugs 816298).
• CHANGED: Graphics related performance improvements (bug 809821).
• CHANGED: Removed E4X support from SpiderMonkey.
• DEVELOPER: Implemented Remote Profiling.
• DEVELOPER: Integrated, Add-on SDK loader and API libraries into Firefox.
• DEVELOPER: DOM/content implementation for <input type=’time’> Associated bugs.
• HTML5: Added support for <main> element.
• HTML5: Implemented scoped stylesheets.
• FIXED: Download Manager page is not updated after clearing private data (777639).
• FIXED: In content UI cut off on small screens (840593).

可以从Google Play Store直接下载到Beta版本，正式版预计今年5月发布。