iPhone 6 hacked

My iPhone 6 was hacked. I had an app from I store named inshorts. I got a notification from that app. The notification on the top was not able to close it . Someone took control of my iPhone . If I tried to power off , since notifications stays on , I was not able to slide it . U know.

Someone hacked or is it a bug . Only after 10 hours , I was able get rid of it .

Any advice ?