iPattern is an open-source vector illustration app. It was designed from scratch for the iPad. It supports paths, compound paths, text, images, groups, masks, gradient fills, and an unlimited number of layers.
iPattern was designed with performance in mind – it can easily handle drawings with hundreds to thousands of shapes without bogging down. Export your finished illustrations directly to your Dropbox as SVG or PDF.
Features:
• Very high performance. Select, scale and rotate hundreds of objects with zero lag.
• Create arbitrary bezier paths with the Pen tool.
• Create compound paths, masks and groups.
• Create text objects.
• Place photos from your albums.
• Boolean operators on paths (Unite, Intersect, Exclude, Subtract Front)
• Powerful scale and rotate tools.
• Gradient fills with interactive editing on canvas.
• Arbitrary stroke dash patterns.
• Swatch library.
• Unlimited layers per drawing.
• Rename, rearrange, delete, hide and lock layers.
• Adjust layer transparency.
• Snap to grid, points, and path edges.
• Isolate the active layer for easy editing.
• Email drawings as SVG, PDF, PNG and JPEG.
• Send SVG, PDF, PNG, and JPEG directly to your Dropbox.
Get the source code and contribute: https://github.com/zaxf/iPhotoshop