holga film is obviously the same as arista edu, which is probably the same as the Foma since that is the factory where it is made -- Arista edu also gives off that green color when you dump the developer out, and more when you dump the stop bath out, so be sure to rinse it well between the stop bath and fix or it will turn your fixer green too.
it is the anti-hilation layer. No biggie. Very colorful. But if you want the same film for less money, buy arista edu.