As I have stated in other posts, the "Hangouts Dialer" app allows you to make calls over the data connection without WiFi and still be able to surf the web. (Please note, this app is different from "Hangouts", it is "Hangouts Dialer" by Google Inc.)
This works on my S5, and it should work on any device that can install the app.
This has not been suggested by any of the Sprint Agents in any of the posts I have seen. I have seen suggestions to use Skype and other VOIPs, but there are some charges and they require a WiFi signal.
This is very confusing because if the app is able to make calls using the data network, then why doesn't Sprint set up the default dialer to do the same thing if there is no WiFi connection? I do understand that this would increase the load on the data network, but you are losing customers at a significant rate due to this issue. Anybody who needs to be on the phone and confirm appts, emails, etc with the person/client/coworker they are on the phone with is not able to do so. This is a monumental step backwards that is inexcusable with todays technology. Waiting for VOLTE is not a solution, as the time frame on this is not guaranteed.
Please consider my suggestion for the default dialer app. Google already has it functional in the Hangouts Dialer app, so there is no reason it can't be done.