New Features in Ver 2.2.0

・Features
　・Options
　　A current value is displayed while a thumb is being moved.
　・UI
　　Change appearance slightly.

・Others
　・For Developers
　　Refactor code.
　　Fetch API replaces XmlHttpRequest.

New Features in Ver 2.1.0

・Others
　・For Users
　　Fix problem which Firefox disable the volume control after a previewer plays a silent video. Edge does not have this problem.

New Features in Ver 2.0.3

・Others
　・For Users
　　Fix problem which some values of settings are not displayed in the option page until it is modified.
　・For Developers
　　"initializeOptions" remove all settings instead of setting default values.

New Features in Ver 2.0.1

・Features
　・General
　　Support a page which is generated dynamically. This impacts performance slightly. You can disable this feature if you don't need.
　・Options
　　Refreshing option has been added.
・Others
　・For Developers
　　A step attribute for interval have been changed to 0.25.

New Features in Ver 1.2

・Features
　・Options
　　Delay option has been added. This is the value until the previewer appears. Default is zero seconds(no delay).
・Others
　・For Users
　　Performance improvement.
　　Fix problem which the border which means loading does not disappear.
　　Fix problem which the layout of English options in the popup is broken.
　・For Developers
　　Each previewers will never add to the body element if it is disabled. In previous versions, It is added even if it is not used.

You can enable / disable audio, images, pdf and videos at the option page.
Setting values become visible, it make you easy to control options.
Fix the problem which it tries to open 'tiff' image files even if firefox does not support the type.
Fix the problem which it tries to open 'mkv' video files even if firefox does not support the type.