I super love "playing" Zombies, Run! - the story missions are fun and are getting me outside and exercising, which is super cool. Ideally, I would like to alternate my story runs with supply runs to ...
In Zombies, Run! as you run you collect various items. At the end of your run you can use those items to upgrade a number of different areas of your base: the Hospital, Comms, Housing, Armory, Food, ...