What are some design considerations for fluid navigation of small-screen displays, e.g. Smartphone or even smart watch screens?

What will be an ideal response?

Simplify: “less is more”
Strive to reduce or eliminate data entry
Learnability is key
Consider use frequency and importance
Plan for interruptions
Use of contextual information
Make clear what is selectable and what is not
Leave room for scroll and swipe gestures to avoid inadvertent actions
Consider relegating less important functions to other platforms