+1. I use it a lot. Extremely handy, a great idea. So many times it saves needing to return to the home screen or getting into the app drawer.
Why can't you use the eBook reader or browser you want?
I don't have a Samsung, but I can't believe there's no way to turn GPS off. Even left on, it should not drain the battery. I leave GPS on all the time with no battery bit. If there's no GPS icon in the top bar, then it's inactive. It should only be active when needed, like when using maps. But, no GPS icon, no power used.
Android since v1.0. Linux since 2001.