Now. Where do I get this for my kindle? Add a play/pause button and a (continuous) knob to tune the speed (with reverse?). An option to jump back a sentence or

Now. Where do I get this for my kindle? Add a play/pause button and a (continuous) knob to tune the speed (with reverse?). An option to jump back a sentence or a paragraph? Or show me the current position on the actual page? (Some way to make spacial position meaningful.) And I'm pretty sure I'm sold.