This is a great battery pack if you don’t have a USB C device. It comes with two cables built in, one for micro-USB and lightning for iOS devices (and can simultaneously charge both), has a USB port for another device, and even a built in LED flashlight (which is very useful). I find a very handy gadget for day to day use and very food for traveling (via the Wirecutter).
I’m surprised there are a couple of these card shaped, omni tools out there; basically, they pack a few tools in one card. They’re kind of like swiss army knives, minus the knife. The one I use is called the Pocketmonkey. I keep it in my wallet for the occasional screw driving and measuring, but I’ll admit the bottle opener is what I primarily use it for.
I found the Bluapple Produce Saver after looking for a way to preserve produce longer than usual. I tested this out with my neighbor and he noticed great results with this and decided he wanted his own as well as it did help save a lot of the groceries he was buying.