You must collaborate with Procreate
Pixiv Sketch reminds so much Procreate and Behance in one bottle. But you should add more brushes and brush studio to edit brushes and make own brushes. Also it will be so good if you add quick shape or shape tool. And maybe export and import in different file formats. Like PSD, Pixiv, PNG, JPG/JPEG, Tiff. And if 3D mode will be available in Pixiv sketch, I’ll be of ninth cloud!