  Searching for relative mobile user interface (UI) design examples can aid
interface designers in gaining inspiration and comparing design alternatives.
However, finding such design examples is challenging, especially as current
search systems rely on only text-based queries and do not consider the UI
structure and content into account. This paper introduces VINS, a visual search
framework, that takes as input a UI image (wireframe, high-fidelity) and
retrieves visually similar design examples. We first survey interface designers
to better understand their example finding process. We then develop a
large-scale UI dataset that provides an accurate specification of the
interface's view hierarchy (i.e., all the UI components and their specific
location). By utilizing this dataset, we propose an object-detection based
image retrieval framework that models the UI context and hierarchical
structure. The framework achieves a mean Average Precision of 76.39\% for the
UI detection and high performance in querying similar UI designs.
