Facebook says it developed these tools in order to make the time people spend on Facebook and Instagram "intentional, positive and inspiring." "Our hope is that these tools give people more control over the time they spend on our platforms and also foster conversations between parents and teens about the online habits that are right for them" Facebook said.

To access the tools, go to the settings page on either app. On Instagram tap "Your Activity," and on Facebook, tap "Your Time on Facebook." At the top, you'll see a dashboard showing your average time for that app on that device. Tap any bar to see your total time for that day. Below the dashboard, you can set a daily reminder to give yourself an alert when you've reached the amount of time you want to spend on that app for that day. You can change or cancel the reminder at any time. You can also tap on "Notification Settings" to quickly access the new "Mute Push Notifications" setting. This will limit your Facebook or Instagram notifications for a period of time when you need to focus.

These updates are rolling out soon on Facebook and Instagram.

The social network earlier this year pledged to change the mix of its news feed to emphasize conversations that are meaningful between friends and family, as opposed to content designed specifically to go viral. The changes have affected how much time people spend on the site, which could in turn affect Facebook's ad revenues. The company has said that it expects sales growth to slow in the coming years - and revenue fell short of estimates in the second quarter.