I have an iPad and Comcast. With the "Watch ESPN" app, I can watch live programming on ESPN, ESPN2, and ESPN3. The app has selections for different sports and when you select a sport, it shows what is on that day. Since I don't have 3G or 4G capability with my iPad, ESPN is only available if I have WiFi access.
On a trip to Chicago, I was able to watch live ESPN in my hotel rooms via WiFi. (That's because my dear spouse was hogging the TV watching HGTV and getting ideas how to spend money!) Hope she doesn't read this.