Built-in language packs:

English, Vietnamese, Chinese Simplified, Chinese Traditional, Czech, French, German, Cyprus (Greek), Greek, Hungarian, Italian, Japanese, Khmer, Korean, Polish, Portuguese (Brazilian), Portuguese, Russian, Serbian (Cyrillic), Spanish, Swedish (Finland), Swedish, Turkish.

New:

• Support viewing RAW formats by taking advantage of Windows Imaging Component (WIC) - Windows 7+
• New file type icons for associated extensions.
• Display "A new version is available" in menu.
• Full support for Portable mode.
• Double click to view actual image size.
• Ability to display / hide hidden image files.
• Add "Zoom to fit" button to toolbar.
• Add support for real time resizing.

Changed:

• Removed Share to Facebook, Extension Manager, Settings, About buttons on toolbar. 
• Add "Autosave after rotating" option.
• Improve full screen mode:
  • Image's height fits the window automatically.
  • Hides the thumbnail bar automatically (same as the toolbar).

Fixed:

• Unhandled exception when 3 or more new images are moved/copied into the folder in which the current image is being viewed.
• Windows number format minus sign causes error on startup.
• Keep maximized window after exiting full screen.
• GIF image file locked after viewing.
• Thumbnail line width resets after closing window.
• Unhandled exception when canceling UAC prompt for "Create new language pack".
• Set as Desktop Background changed current the Fit Option in Windows 10.
• Unhandled exception when closing two windows.
• Image does not scale to fit when using title bar maximize/restore buttons.
• Drag and drop image from same folder doesn't open the image.
• Fix hamburger menu disappearing
• Unhandled error when cancel the Register Extensions operation.

For the complete changes see the changelog.