In much the same way as most computer problems can be solved by switching your computer off and then on again, the first thing to do if your app won’t open is to switch your phone off and on again. If you are still having trouble, uninstall it from your phone and then install it again. For help uninstalling Hailo for your phone go here for Android and here for iPhone. If this still doesn’t resolve your problem please let us know and we’ll see what we can do to help.