RetroUI allows you to see the Taskbar and Start button while the Windows 8 Start screen and when Apps are running.
More about RetroUI - Windows 8 Start Menu
Thinix RetroUI™ Pro is easy to use software that allows you to skip the Start screen in Windows 8, brings back the start button and start menu, makes the taskbar visible from the Start screen, allows you to resize Windows Store apps, allows you to block Windows HotCorners, and includes TabletView. RetroUI Pro makes Windows 8 far easier to use with features like allowing users to press the Windows key to return to the classic Windows desktop at any time. Multiple display users can easily span Windows 8 Apps across more than one monitor. Learn more.