According to research, about half of users use their phone with just one hand in any given situation. This behavior limits the areas they can comfortably reach with their thumb. The safest way to hold a phone in one hand is resting the bottom end in the palm. Another 15% of people hold them in the palms with both hands. Both ways to hold a phone make the top of the screen harder to reach.
As shown in the examples above, the green areas of the phone are the most reachable.
Accordingly, Kirigami's phone components are optimized to favor the center or bottom of the screen for primary interactive elements, while placing secondary elements into drawers which can be opened from up to three different points of the screen.
Kirigami also features the "overscroll" feature, which allows you pull down the top part of the screen in case you have to reach e.g. the topmost items of a list.
When using Kirigami on a phone, make sure that often-used controls are never placed at the top of the screen, and also avoid the screen corners in general.