When a lick or melody comes to mind one the few times I'm away from a guitar, I use a virtual piano app to play with it and check how it sounds. But now I got an idea with a bend. How can i listen to it or play around with it without a guitar?
Most piano-like synths have a pitch bend wheel (or simply "pitch wheel") or touchpad with similar control.
Any virtual MIDI app with track envelope capability ought to be able to attach a pitch shift to an envelope.
So look for apps/applications that allow envelopes or state that they have pitch bend capability.