iPad Apps to Smooth lines

ibis Paint X is a popular and versatile drawing and painting application designed for mobile platforms, offering a robust suite of tools for digital artists. It boasts a massive library of brushes, filters, blending modes, and supports layers, pen pressure, and recording timelapses.

Autodesk SketchBook is a powerful yet intuitive digital drawing and painting application designed for artists, designers, and creative professionals. It offers a comprehensive suite of tools to create stunning artwork on various platforms, focusing on a natural drawing experience.