Hilton app not workong

I have had the app and recienlty got a mesage it wiwll not work with my phone. My version of phone sytem is listed as a version high enough to work . I uninstalled the app and now get a messag ethat my veriosn is no loner compatable , even though the 6.0 or higher is required and my phone is a 6.0  it will not download saying it is no longer compatable/