Hi

SketchUp on the iPad. This sounds pretty interesting to me.

I have tried several 3D programs on the iPad. Shape3D and Umake
for example, but both were too clunky for me.
And Shape3D tooooo.... expensive.

Currently I have Nomad 3D installed on my iPad and am very happy
with it. Nomad 3D is actually known as a Sculpting app. But it can do
quite a bit more. As this short video shows.

It is from Ilya Tulyakov, in this video he switched between
Nomad 3D and Procreate. He use Procreate to sketch some
parts bevor modeling.

https://www.youtube.com/watch?v=kp6LEVv30lY