If a paid app stops working, can I get my money back?

For example, the application Say it right! is using the Forvo third-party service. I guess the app can stop working eventually (for example if the API changes, or if the third-party service terms change) Are paid apps purchased from the Google Play store supposed to work for lifetime? **Edit**: The previous example costs 1 euro, and obviously if it stops working that would be no big deal. But the same applies for apps that cost 20 euros or more. I wouldn't be happy if an expensive app stops working after 3 months, and I'm curious if Google has a policy for this on its Play store.