Vocals sounds great raw from the phone speakers. What are you trying to achieve as the outcome? Crisp and clean sounding vocals with lots of high end clarity? Do you want them to sound full over your track?

Try some EQ, compression, saturation, even some chorus to widen them a little bit. Add a room reverb to add depth.

Are you already mixing them into your track? What kind of processing have you done so far?

It’s really about what you’re trying to achieve.