My tired old iPhone 6 could really use a new battery. So, earlier this year I was pleased to learn about the $29 battery replacement program offered by Apple. Unfortunately, the whole experience left me sorely disappointed.
The program requires one to contact Apple support who will then order a battery to be sent to the local Apple store of your choice and schedule you with an appointment for the change out. I did that. The Apple representative was friendly enough and assured me they would get the battery on order right away.