Deleting an App that refuses to go away
I usually do the same thing when installing or deleting stalls, put the device in airplane mode, turn off WiFi, turn off Bluetooth and power it down. 

When it starts, delete the app, then enable communications as desired. 

When that fails, it’s easy to collect diagnostic information and send to Apple, but usually it’s a stuck network or storage issue that starting with a clean OS start in trolls whatever process was jammed.