AFAIU on iOS there are two types of deep linking. 1) Universal Links, which allow owners of domains to launch an app instead of Safari. For example, you might own the domain myawesomeapp.com, and therefore can redirect urls to e.g. myawesomeapp.com/do_things to launch your app. 2) Protocol links, these are completely locked down by iOS and there is no way to subvert them. For example, mailto links always open the mail app.