With WindowTop (FREE for Windows 7 - 10) you can pin any window on top of other windows, enable window transparency (so you can see through the window) and even click through transparent window.

WindowTop also comes with exclusive features such as "Shrink Window" - an innovative way to minimize windows (video time: 1:42), and the Dark/Reading Mode (video time: 1:29)

DOWNLOAD (v2.0.5)

Set Window On Top
Easly set any window on top from the toolbar menu
Click Through
Only see the window without interact with it
Set Transparency
Easly set window transparency from the slider in the toolbar menu and instantly see the result
Shrink Windows
Innovative way to minimize windows - it will not minimize to the taskbar to keep your taskbar clean as you like. it will make the window smaller so you have the space you need.
Dark/Reading Mode
Easly set the window to be dark. Useful for coding, and for reading at night. This should ease the eye strains!