Software deceit is relevant (7)
I believe the answer is:
applies
'is relevant' is the definition.
(I've seen this before)
'software deceit' is the wordplay.
'software' becomes 'app' (software application).
'deceit' becomes 'lies' (I can't justify this - if you can you should believe this answer much more).
'app'+'lies'='APPLIES'
Can you help me to learn more?
(Other definitions for applies that I've seen before include "Makes a request" , "Fills in form for job" , "Is relevant" , "Implements" , "Makes use of" .)