People can exchange numbers with each other and leave the app.
Simple configuration, lightning fast, etc.
Both Android and Apple have policies where developers can decide whether or not they include advertisements within their apps or if the app is ad-free and charged.
Push notifications allow alerts about new matches or messages when users are not in the app.
Users can search for profiles that fall within a specific mile range.
Not even an API key required.
Notes on using different Operating Systems and services relating to DevOps, for reference.