In one embodiment, a method includes determining one or more applications on one or more first client computing devices of a first user of a social-networking system; determining one or more second users of the social-networking system that are connected to the first user within the social-networking system; determining one or more applications on one or more second client computing devices of the second users; comparing the applications on the first client computing devices with the applications on the second client computing devices; determining one or more application recommendations for the first user based at least in part on the comparison; and sending the application recommendations to the first user.