The primary reason the app is not updating is because the device is not connected to the Internet. Going to Safari, or similar web browser, to check and see if a page loads is a quick and simple check.
A user can see if the device is not connected to the Internet when the gear icon goes red in color at the bottom left of the screen. If the gear icon is yellow in color it means a sync is occuring. Also, he can watch the sync clock at the upper right of the Incident list screen. The sync clock should reset every ten seconds. If it goes beyond ten seconds it means the device is in a poor or disconnected cellular state.