It's no secret that Facebook, the social network that more than 1.5 billion people around the world use, is looking to get to the next billion line. In conjunction with this, Facebook Inc., the operator behind the social network, has made efforts to tap different markets, even those that have slow Internet connection.

However, the next billion won't be reached if it doesn't retain the current pool of users. Hence, Facebook launched Notify, an app that promises to deliver tailored notifications based on the user's interest, as well as the sources he or she is subscribed to. Notify separates itself from Facebook's main mobile platform by having the notifications persist even through the lock screen.

"You'll receive notifications, delivered right to your lock screen," writes Facebook. "To see more, just swipe or tap through any Notify notification to open the link in the app's browser where you can read the full article, watch the video, or view the site."

Suffice it to say, this is Facebook's way of getting users to be more active on the social network. With more activity, more ads can be shown and thus, more revenue. Nonetheless, it's easy to see how this app can be helpful, especially with the user's freedom to curate the notification he or she receives.

Users can choose the sources they want to feed them notifications. This is especially useful for people who need constant updates regarding things that concern them. End-of-game summaries from stations like Fox Sports, local weather forecasts from The Weather Channel and breaking news from CNN are some of notifications users may choose to receive on Notify. 

Moreover, Notify will suggest relevant stations based on the user's Facebook profile. Users will also have the option to add notifications that interest them to the "Saved Notifications" list for later reading. This can be done with just a simple swipe.

Furthermore, every notification receives within 24 hours will be compiled by the app. The alerts can also be shared to friends via Facebook's built-in messaging platform, text message and email.

While the idea seems favorable, Facebook is yet to divulge how it plans to filter the notifications since stations may exploit the app's availability and feed so much content that it can be considered spam. Where will the control need to be? The users? The stations?

The app is only currently available for iPhone users in the United States. The app's launch on Android is expected to follow soon.

Below is Facebook's promotional video for Notify.