Quick question for those familiar with iOS and Android.
One thing I love about W10m is the magnifying glass search button. Whatever app I'm using, I'm one touch away from search. I use search for everything from spelling, currency conversions, weather.. etc.
Android is similar, you just hold the center button until Google Now or Assistant (if on 7.0 or 6.0) appears.
On iOS, you can pull down the notification shade and search that way via Spotlight search.
I have the Bing app by the main home button on my Android phone. Very easy and convenient to use. But like the user before me said you can map Cortana to the home button as well.