Temporary Lock Keeps Your Droid Secured - AlphaDigits
Lock Me Out - App/Site Blocker - Apps on Google Play
Use Guided Access with iPhone, iPad, and iPod touch - Apple Support
How to Easily Lock Any App on Your iPhone or iPad Behind Passcode or Biometric Authentication « iOS & iPhone :: Gadget Hacks
Is there an app that can lock my phone temporarily? I want to turn it into a 'dumbphone', essentially, that is only able to call and text for productivity purposes. - Quora
How to Lock Apps on Android 6.0 Using Fingerprints
iPhone trick lets you temporarily 'lock' touchscreen and childproof your phone - Mirror Online
12 Best Focus Apps to Keep You off Your Phone - TechWiser