There's another forum for the S5 that gives you a way using an alternate launcher to access download booster. The one thing stopping it once turned on is the ability to turn on the specific mobile network mode.
Nova launcher allows you to add shortcut then go to settings and find download booster. It's one of the selling points for the phone that I enjoy. I'm from a rural area so when I go home to visit I want to combine the connections when needed.
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