Some of you may know this situation:
You sit around your computer with some guys and really, really need to go to toilet or something but you don’t want that these guys play with your computer/laptop.
So you lock your screen and went away. As soon as your back you type in your password (hopefully no one will see it). Maybe its really long and takes some time. Wouldn’t it be great your computer locks itself if you went away and unlocks if your back?
No problem!
You can use the bluetooth function of your cellphone (or other bluetooth devices) in combination with Blueproximity to do exactly that.
Just do the following steps:
first you have to install Blueproximity
apt-get install blueproximity
Now set you cellphone to visible and pair it with your computer/laptop.
In Blueproximity you should see your device
if you don’t just search for so that it appears in the devices filed.
Select it and click “use selected device” (left pic)
Now you can do your proximity settings.
Set the distance and duration that the device have to be
away to lock the screen and same for unlocking. (right pic)
As long as this window is open Blueproximity is in simulation-mode.
It shows the distance between the device and itself but don’t lock the screen
If you close the window it gets activated.
Now step away from your computer and try it 
Nice one… isn’t it?
Btw. in the locking tap you can specify a command instead of locking the screen. Any ideas what you can do there?
Write it in the comments!
And for those of you who don’t use Linux try BlueLock instead of Blueproximity. I never tried it myself but some others say its the same!
In Blueproximity you should see your device if you don’t just search for so that it appears in the devices filed.
Select it and click “use selected device”
