Listen to me: some apps stink (4)
I believe the answer is:
psst
'listen to me' is the definition.
(I've seen this before)
'some apps stink' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'PSST' can be found hidden inside 'apps stink'.
(Other definitions for psst that I've seen before include "attempt to attract attention" , "Notice me" , "Sibilant sound to get someone's attention" , "Sound used to attract someone's attention" , "Call to attract attention" .)