This app was mentioned in 2 comments, with an average of 2.00 upvotes
Spacedraw is probably your best bet for modeling. You can export stuff back to Blender with .obj files. Photoshop Touch could work OK for texturing. I haven't used either since I don't have an Android tablet or phone. You're probably better off using Blender on a laptop if that's an option.
Aparrently Spacedraw (Android) is good, though I haven't tried it myself.