BBM originated as an alternative to Yahoo chat rooms and SMS messaging after their rise in popularity. While it faces competition from iMessage and WhatsApp, BBM still has over 50 million active users, up from 28 million last year, appealing as a social tool over iMessage. RIM has integrated BBM deeply into its devices, allowing sharing of photos, links, app recommendations, and a social music feature called BBM Music. Currently, WhatsApp has co-opted the BBM concept by working across all smartphones without requiring special plans, whereas BBM is limited to BlackBerry devices and may require additional charges.