Device runs application (4)
I believe the answer is:
ruse
'device' is the definition.
(device can mean a scheme or ruse)
'runs application' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'application' becomes 'use' (I've seen this in another clue).
'r'+'use'='RUSE'
(Other definitions for ruse that I've seen before include "Trick designed to deceive" , "Clever stratagem or plan" , "trick played" , "Sure to be a trick" , "Deceptive device" .)