Kershaw PT-1 Keychain Multitool | $5 | Amazon
Kershaw’s PT-1 is a keychain tool with three separate functions: a pry bar, a flathead screwdriver, and (what you’ll use it for 99% of the time) a bottle opener. I’d also add a fourth though: packing tape breaker. It’s not a blade, so it won’t slice open a package, but it’d be useful for getting them started so you can claw them open with your fingers.
This was on sale for $5 last month for a time, but swiftly sold out. Now, it’s back in stock for the same price.