The new App Lock feature on Facebook Messenger will help users prevent others from accessing their private messages.
Messenger users can find the App Lock feature in the new Privacy prefs section.
You candownload Facebook Messenger for iOSin the App Store.
This will be similar to the message controls on Instagram.
A similar feature already exists on Instagram and WhatsApp that blurs images in the message requests folder.
source: www.techworm.net
