The unofficial SnapChat client on BlackBerry 10, Snap2Chat, just got a small but huge update. The app was approved to run in headless mode which means it now is running even without an active frame. Thankfully the developer has made Headless mode optional but I highly recommend it. You can now get notifications without having to make sure to fire up the app.
Check out Snap2Chat in BlackBerry World. There is also a free Lite version available.