Consider that the 10% must also include Windows Phone users (as there is no Swarm app in WP). 'checkin users' probably means something like "active daily users

Consider that the 10% must also include Windows Phone users (as there is no Swarm app in WP). 'checkin users' probably means something like "active daily users on platforms where we have released swarm" and 'moved over to Swarm' means something like "has at least 1 checkin using Swarm". This is what I like to call "counting for marketing professionals".