Normally a great app but I have been having issues lately. I turn my phone off at night and have found that I never receive those messages that are sent to me while my device is off. This never used to be an issue, they would all come through within a minute or so of turning the device back on. I have tested this several times now with different friends, all of their messages show 'delivered' next to them once I turn my device back on but they never come through on my end.