reflection analysis tools), it could be much efficient to only download and analyse (the small set of) relevant apps. To this end, we provide to the research community various metadata of Android apps that are expected to be used by users of [[**AndroZoo**]{}]{} to pre-select relevant apps. Furthermore, since it is usually unavoidable to compute the metadata of Android apps for supporting further analysis, our effort, which is done once, could potentially avoid the same work being repeated by other researchers, resulting in less computing resources spent in our society.

**Outline.** The remainder of this article is organised as follows: Section \[sec:app\_collection\] presents the architecture developed to collect Android apps while Section \[sec:metadata\_collection\] presents the collection of various metadata associated to [[**AndroZoo**]{}]{} apps. Section \[sec:implications\] then enumerates some implications that leverage [[**AndroZoo**]{}]{} to perform various analyses. Finally, Section \[sec:leveraging\] and \[sec:conclusion\] discusses some limitations and provides concluding remarks respectively.

The AndroZoo apps and metadata are available at the following website:

<https://androzoo.uni.lu>

App Collection {#sec:app_collection}
==============

For most app sources, we developed a dedicated web crawler, where every candidate app which is available for free runs through a processing pipeline that: (1) Ensures this app has not already been downloaded; (2) 