Duolingo Plus is not worth it and there is not option to unsubscribe!!
I wanted to try plus because I am in another country and don't always have access to wifi and it barely/doesn't work when I don't have wifi and it is not worth the cost at all. Any advice on how to unsubscribe and keep the app? I love the app, but upgrading is definitely not worth it!
You can unsubscribe via the App store on your device.
Android help for "Cancel or change a subscription on Google Play"
IOS help for "View, change, or cancel your subscriptions"
There was a discussion about it, eg. https://www.duolingo.com/comment/22202238/Introducing-Duolingo-Plus
No sure about a clear solution, I guess Zig_Zag is right.
I guess I'm in some fortunate category that doesn't have ads. I know I've never seen a single ad in the Android app. I've occasionally but rarely seen them on the website. (Now, watch, they'll give them to me.).
I've ripped the latest version of the Android app off, anyway, and reverted back a version due to the darned timed practice. Who can type fast enough in a phone or tablet to even get the first question?