Efficiency, yes. The second part is a little misguided though. The different gears in a transmission allow the vehicle to move at your desired speed while keeping the engine’s speed low, thus reducing fuel consumption.
Power to fuel consumption isn’t really a thing afaik. Naturally, a slower spinning engine will use less fuel.
Finally, some sanity. Just because it’s apple, doesn’t mean it’s okay to build a business model on piggybacking off their service. I know “apple bad” but I don’t get why people are defending Beeper.