I've seen eco-friendly versions in many health-food-type shops.
However, the best bet is to use containers with lids or paper bags or similar. Those lock & lock type containers are good. Or I have reverted to doing what my mum and gran always did - put food in a bowl with a small plate on top as a lid, or the other way round, food on plate with cereal bowl to cover. This works a treat.
For sandwiches in lunchboxes I either use a lock & lock box (I like the ones with removable dividers in, although I have to take at least one divider out to fit the sandwich in!), or I use a larger plastic lunchbox and inside that is a variety of different sized containers holding sandwiches, fruit, cake etc.
in germany you can buy various sizes of "showercap" for covering food in dishes and microwaving. They last for ages as you just rinse and reuse. For sandwiches you need tupperware or paper bags. DS1 takes sandwiches every day to school. he has a crayola sandwich shaped box, a baseball shaped box for the carrots and a refillable bottle of water. We havent used clingfilm in a long time.