There is only one type of stitch in machine embroidery. It's the same interlocking stitch that was invented in the earliest form of a sewing machine. All stitches, in modern machine embroidery are series and patterns of this simple running stitch. All embroidery can been seen as graphs of straight connected lines, between various points. Since sets of colored lines are the core medium of all embroidery. Touch Embroidery has a set of tools that allow you to, in the app, edit and create lines which can be saved as embroidery patterns, and sewn on an embroidery machine.