So you're at a gathering and your Android phone's about to die. Not only that, so is your friend's iPhone. Basically, in a few minutes, all the things will be dead. You could beg around for a couple of chargers, but then you'll have to trust that no one will take your device when you walk away or deal with being tethered to the wall until you have a reasonable charge.
This is when you want an external battery pack like the Choetech 15,600mAh one available on Amazon. The battery currently goes for $40, but if you enter the coupon code YDUKCSCX at checkout, you can take $8 off.
Since this power source is portable, you can keep it with you in a bag or on the table. And as a Quick Charge 2.0 battery, you won't have to leave your phone plugged in for long before you're back in action. You can also charge it back up similarly fast.
Choetech's power bank comes with two USB ports, with one being blue and capable of charging at up to 2.4 amps. The black one is 5V/1A and better for when you're not in a hurry. The pack can charge Apple devices as fast as their original charger and comes with lightning port input.
To repeat, you can get this thing for $32 by heading to Amazon through the link below. The coupon code will expire in 10 days.