Yes if you have drafty windows and cannot afford to replace those drafty windows and you have cold air coming through those windows then yes the window film does help keep cold out and helps keep the heat in the house.
You place the window film over the window and then use a hair dryer to shrink the window film tight enough and it seals out the cold air.
Then you can remove it when spring comes around.
I used window film on apartment windows that were drafty and then added some thick blankets over the windows as well.
If you don't want to see out of the window you could also place some of that foam inside the window where you buy those sheets of insulating foam and then cut it to size and place it in the window until winter is over and then remove it when you want to look out the window again.