WhatsApp is bidding farewell to older mobile operating systems as the year draws to a close. Specifically, it's ending support for Blackberry OS (including BlackBerry 10) and Windows Phone 8.0 and older on December 31st. Although the Facebook-owned messaging app will continue to work on these platforms, users won't be able to create new accounts or re-verify existing accounts. Oh, and Whatsapp claims its app could stop functioning at any time, so maybe it's time for that upgrade.