hii every one my blynk app showing connected and disconnected always every 15 seconds. this would irritate me . i switch off the offline notification status in the status eventhough it is showing. what it is mean can you explain
Sounds like your device is resetting or losing connection every 10-15 seconds 
You would need to investigate the actions of you device closer… perhaps using the IDE serial monitor… to see what if any error messages are showing.