Input Forager is a user-driven adaptation approach that enables users to flexibly borrow different embedded inputs from smartwatches, smartphones and tablets, then map borrowed inputs to interaction-events that effect Head Worn Display's (HWD) contents. Our approach allows users to form a diverse set of interaction paradigms that involve different device combinations, input types and interactionevent mappings that supplement the limitations of HWD's interaction methods. Such adaptation flexibility allows users to form interaction patterns that correspond to various HWDs' usage contexts. Accordingly, we developed a prototype that comprised an adaptation-client that ran on a smartwatch, a smartphone and a tablet, then carried a user study to evaluate Input Forager within a scenario that resembled HWDs usage contexts. Results indicated that our approach enabled users to reflect both common and distinct input and interaction-mapping preferences. Moreover, qualitative analysis revealed an overall positive usability results, while shortcomings were mainly in the adaptationclients' user interfaces. Finally, we presented the future direction of our project.