How to cancel subscription on iPhone
After much fuming and fussing I was able to cancel a subscription to Yokee on my iPhone. It's not in the App, as some posts led me to believe. You go to your iPhone settings, and click on your name. That brings up a list of things, one of which is Subscriptions. Hit the arrow to the right to open it. Inside should be listed any subscriptions you have, and inside each subscription somewhere (toward the bottom usually) is an option to cancel the subscription. If the subscription you want to remove isn't listed under Subscriptions, it may be under iTunes & App store. Hope that helps!
iPhone SE, iOS 11