picons are usually small graphics files or icons which are used to customize GUI elements or objects on many, typically older, devices, such as TVs, set-top-boxes in which these files are used to assign custom icons for individual TV programs. In most cases picons are just renamed GIFs or JPEGs, not really in some kind of special format, just using specific file extension and pixel size. You do not need special tool to make or convert them, just any graphics editor, proper resolution (8x8 or 16x16) and just rename the extension.
Updated: July 21, 2023