Hi Burlesot,
Thanks so much for your comment. Have you tried Morphi (www.morphiapp.com)? It's a simple, powerful 3D modeling software available on the iPad and Mac, coming soon for Windows and Android. It's similar to MakerBot's Printshop but with more features and works great with all Ultimakers. You can reach out to the developers at hello@morphiapp.com. Good luck!