The app will freeze if your SD card is too fast or too slow. For the K-102, use a card formatted to exFAT . Do not use U3 cards; the camera’s bus cannot handle them, causing the app to disconnect.
For drones, simply entering the "Start" or "Monitor" mode in the app after connecting to the WiFi signal should bring up the live feed. Quick Troubleshooting kh k-102 camera app