I am trying to get my hands on data about app usage (iPhone and Android) by user. The users would be anonymised I assume, but I would need to link them to the range of apps they use or have installed on their phone. Is this data available or is it only available at an aggregated level?
authors of the BAM application for android may have some data you are asking for. It can recommend apps based on other users that have the same set installed.
E.g., blind users if they connect - they would recommend this way apps to each other.