irritating pop up window

i keep on receiving an irritating pop up every few seconds

that says uimmora.app cannot be opened because the developer cannot be verified.

macOS cannot verify that this app is free from malware

this file was downloaded on an unknown date.

and this pop up window gives me 2 options 1- move to trash 2- cancel

when i press move to trash

another pop up says uimmora.app could not be moved to trash. please move this item to trash manually.

i searched manually for this app but i could'nt find it in my device

please help