Heya, this is for those of you that have an iPad. Maybe you haven't even considered using it for painting textures, but I'm here to tell you it's not just possible but also a pretty great experience in Procreate. I put together this little guide on how to set up a project to be able to paint seamless textures:
https://www.artstation.com/blogs/ptgrant/EeyO/paint-tiling-images-in-procreate