Draw Grid on Image is a free iPhone app developed by Thang Do. It is a useful grid tool that allows users to maintain the proportion of drawing objects. With this app, you can easily add a layer of grid on top of your image, ensuring accurate and precise drawings.

The app offers six different types of grids to choose from. You can opt for a rectangular grid by setting the number of rows and columns, or by specifying the row height and column width. Alternatively, you can select a square grid by setting only the number of rows, only the number of columns, or just the row height or column width.

In addition, Draw Grid on Image provides six paper sizes (A0, A1, A2, A3, A4, A5) and two unit types (cm and inch) to cater to different preferences and needs. You can also customize the line width, ranging from 0.5 to 10, and choose your preferred line color.

Please note that saving grid images to the Camera Roll is only available in the Pro version of the app.

Overall, Draw Grid on Image is a convenient and versatile tool for artists and designers who want to maintain accurate proportions in their drawings. Download it now and start creating precise and proportional artwork.