iPhone recordings, can they be cleaned up

So Basically a bit of a sad question, myself and my friend had a wee two piece together, me on vocals, himself on guitar, we had arranged to book into a recording studio to record songs we had written and some covers, just for the craic really, to have for ourselves not to sell or anything.

Unfortunately he got a cancer diagnosis and with lockdown and with how the chemo affected his fingers we didn't get to make the studio and he passed away last week.

We recorded a lot of stuff on my iPhone, just to have as reminder as to how we arranged the songs and I'm wondering if there is a way to clean these up so I could make a cd or put the songs on a memory stick to give to his family.

It doesn't have to be crystal clear but a bit clearer than they are at the moment, is there any software available that could do that? I know it's difficult when the voice and guitar are intertwined on the one recording.

Thanks