The app on Tablet keeps Syncing

The blue bar at the bottom is all the way across from left to right, but the circle in center just keeps going around and around.

Which tablet? What version of the OS?

It is a android Envizen digital tablet. It is 4.4.2 version. I have installed the app a couple times. This time it is almost at the end of the line in blue. But it has done this before, and kept running for hours of syncing.