I have a galaxy s4, pretty good phone. I am tethering using WIFI TETHER ROUTER to my laptop as it is the only one i have found so far that works with this phone. I am rooted. I have inconsistent data speeds. Sometimes I get over a meg per second downloading, but many times I get 40 kbps or less. My upload speeds are 4 mbps or more consistently. I have done a speed test and many times it will start off over 1 or 2 mbps, then drop down to the kbps again and stay there. Any ideas on what may be causing this? If you know any other/better tethering apps that would be appreciated also