I wish there were a nice quick way to do lockdown on an Android phone. Right now you have to hold down the power button and tap the lockdown button on screen. Which requires you to pull out your phone and is completely obvious.
Shoot, even a time based lockdown, so like if you don't use biometrics in the last hour or whatever, then you must use your passphrase. Or any other number of logic conditions like location, wifi connect, finger used...