Jamba Juice is handing out free money! Well, almost. They're offering a $4 credit just for logging into their app. It's valid until December 12th, so you've got a little time to use it. Why should you care? Okay, $4 might not seem like much, but if you're already a Jamba Juice fan, it's basically a free smoothie boost. Or maybe it's the perfect excuse to finally try that exotic flavor you've been eyeing. Hey, free is free, right? Go grab that Jamba Juice credit!