There's a lot of face swap apps out there now that could work. Otherwise, I found this site https://faceswaponline.com/ I'm not sure if it's reputable. Source: over 1 year ago

If he's into Spiderman then maybe he'd enjoy getting comic books? I'm sure there are some special editions etc. Maybe figurines or merch stuff? Could also be a reference to the latest Spiderman movie, you can use a poster or a still image from the movie and replace Spidermans' faces with your bf's (there are face swappers and online programs that do that) and then print it out. Source: over 2 years ago

If you are wanting more organic 3D modeling check out Nomad Sculpt it is only $15 one time. Source: about 1 year ago

There are no good hard surface modelling apps on iPad yet. We do have Nomad Sculpt which is rapidly becoming better and better, but it's mainly a streamlined zBrush clone for sculpting and some model painting. You technically can hard surface model on it, but don't expect anything like Maya/Blender out of it. Source: over 1 year ago

Nomad Sculpt (Limited free version) (Recommended for this section). Source: over 2 years ago

I haven't yet but I have played around with Nomad Sculpt for 3D modeling on the S7 itself. Source: over 2 years ago

While you wait for that feature, there is Nomad Sculpt. Source: about 3 years ago