URL redirects in the Salesforce mobile app

URL based navigation works only in the desktop browser. These browsers are built to handle URL redirects to and from external resources.

The downloadable (iOS based or Android based) Salesforce mobile app, in contrast, does not have URL based navigation, but event-based navigation, using the sforce.one navigation library. As a result, the Salesforce mobile app is not designed to generate an event tied to a external resource URL, and it cannot interpret URL redirects once outside the context of the Salesforce mobile single page app container. 

What this means is that calls to external sites are not guaranteed to redirect back to the same record in the Salesforce mobile app, because once the external resource call has been made, the external endpoint cannot be controlled once outside of the single page app context. The sforce.one navigation library, when used to navigate to an external resource, takes the user out of the context of the Salesforce mobile app, and the navigation history stack is not preserved. Thus, navigating using the back button on a mobile device after these calls are made will not guarantee that a user is taken back to the desired record in the Salesforce mobile app, as they have exited the mobile app context. 

Salesforce Support can troubleshoot issues where the mobile supported sforce.one navigation library sends out a request to an external resource. However, because of limitations on event-based navigation in the mobile app container context, there are no guarantees on how the URL is interpreted once the user is taken outside of the mobile app context. 

Additional Best Practices Document.