1. Main Menu
This top toolbar areas allows you to access the main commands of Pro Viewer.
2. File Explorer
The file explorer is a permanent shortcut to your file system. Click on the small
to unfold folders and browse your file system. Click on the folder name to show its file list.You can hide the file explorer using the close button
. Once closed, the explorer is still visible as a thin vertical band along the left edge of the main window. You can make it fully visible again by clicking on this vertical band, or through menu View > File Explorer.3. Image Space
The workspace holds one or two Playback/Analysis screen. A Playback/Analysis screen has an "Image" area in which the video is played[3], a Key Images area [4], and a Controls area [5], that allows you to take actions related to the video and export images.
4. Key Images Toolbar
When you add Key Images, the toolbar unfolds and shows the Key Images as thumbnails.
You can hide the thumbnails (without removing Key Images) using the button : 
Add a Key Image.
Move a Drawing.
Show the Comments Window.
Use the creation or edition of a label tool. (Text).
Use the free hand drawing tool.
Use the Line tracing tool.
Use the cross marking tool.
Use the angle measurement tool.
Import all the drawings from the previous Key Image into the current frame.
Modify, save or import a color profile for the drawing tools. 5. Controls Space
Go Back to the beginning of the video. 
Go to the previous frame.
Play the video.
Pause the video.
Go to next frame.
Go to the last frame of the video.
Navigation cursor.
Working Zone selection bar
Lock/Unlock Working Zone boundaries.
Set the first frame of the Working Zone to the current frame.
Set the last frame of the Working Zone to the current frame.
Reset the Working Zone to full video.
Loop mode play.
Single mode play.
Save a snapshot of the current frame.
Save a sequence of snapshots.
Save a diaporama of Key Images.
Save a PDF document of Key Images.6. Status Bar
The status bar displays the current state of the work space. It holds the file names of currently loaded videos.
