Today I tested the Screencast Keys with the last version of Blender 3D - version 2.78.
One great addon can be used to share your work over 3D Blender community.
This addon will show the keys and mouse actions into Blender 3D.
The Blender 3D addon can be downloaded from here and then just put into your Blender 3D path: blender-2.78-rc2-windows64\2.78\scripts\addons.
Now next step is to enable it from: User Preferences > Add-Ons > 3D View.
Restart your Blender 3D software to make setting.
The setting can be allow with start under right panel by using key N and will find the Screencast Keys area.
You can also just start working by press the keys: Shift+Alt+C.
The addon is very useful for most blender users.