Don't talk about something downloaded by love poet (6)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

SH (sh! = don’t talk! = a command to be quiet) around APP (something downloaded to a phone or computer), then O (love = zero in tennis scoring). Ancient Greek lyric poet; other ancient writers seem to have admired her work, but most of it is now lost.