It’s one of the core design principles I use when making decisions about implementations. I can share some examples where this mattered.
The app is pretty aggressive about caching. This should reduce the number of unnecessary network calls. Network calls are expensive both for performance reasons and on your battery (try it out, turn on airplane mode and watch your phone last 1 week on a single charge).
Another example is unnecessary computation of changes and of UI elements. This again both increased performance and battery life.