Onavo, the data-security app maker that Facebook acquired in 2013, has launched a new Android app that let users lock other apps on their devices using a PIN code, pattern or fingerprint. 'Bolt App Lock' - from the Israeli company that provides analytics products for mobile apps - adds to the long list of mobile applications that help users lock other apps on their smartphones. "Like the others in this space, the 'Bolt App Lock' lets you lock down other apps that contain personal information, such as private photos or payment details," Tech Crunch reported late on Friday. With the resources of Facebook behind it, Onavo appears to have built a more polished, modern alternative to the existing apps, the report added. But Onavo - and Facebook's - primary interest apparently is not on personal security but about monitoring users' mobile activity and learn what new apps could be taking attention away from Facebook's social network. The app's listing on Google Play explained that Onavo would "collect info about your mobile device and the apps installed on it" and share that with Facebook. Facebook recently began advertising 'Bolt App Lock' directly within Facebook's main navigation on iOS, under the menu item "Protect". When clicked, the link would take you to the download page for Onavo Protect on the App Store. The company has also featured a similar "Protect" link in its Facebook app for Android in the past.