Application is crashing when you are closing it on IOS and Android devices.
This is the error:
NullReferenceException
at UnityEngine.Component.get_gameObject () [0x00000] in <filename unknown>:0
at UIDrawCall.ClearAll () [0x00000] in <filename unknown>:0
at UIDrawCall.ReleaseAll () [0x00000] in <filename unknown>:0
at UIPanel.OnDisable () [0x00000] in <filename unknown>:0