FYI, you can also add those features (lazy mouse, curved lines, isometric and perspective constraints) to any art app (including Photoshop) with the Lazy Nezumi

FYI, you can also add those features (lazy mouse, curved lines, isometric and perspective constraints) to any art app (including Photoshop) with the Lazy Nezumi Pro app. http://lazynezumi.com http://lazynezumi.com