data is active, but slow as all hell

I use an android phone and For the past 2 to 3 days, my data has been so slow that I can't access downloads on certain apps. I don't what it is, but its getting annoying. Usually, I would just chalk it up to t mobile tower troubles. However, I've had a history of my data coverage being so trashy. And it's because of one thing that still don't freaking understand and that: the carrier hub application. Someone explain to what the hell it does and why does my service always get worse when is have to mess for an update or permission or whatever. I've been dealing with this carrier hub bull crap for a few good years using t mobile and it still gets on my nerves.