For OP, is it worth getting? It's free, so sure, it's worth that.
Next question, is it worth USING? Well, that depends. For me it takes a very loooong time to connect, and it fails to do so at all in most cases with my iPhone6 and my wife's iPhoneSE, ditto my and her iPads. When I first got my 2012 SL new, I used the app several times a day both to learn and see the new ways I can capture my driving experience, and it was something I'd never had for a vehicle before delivering stuff beyond what OnStar and its other automotive companions delivered. Over time, I've cared less and less about the details provided and have found LEAFSpyPro far more useful to me for those bits of data. Still need the Nissan app to control the pre-heat/-cool though and that's my only use for the app today. And it's a crapshoot if it's going to work even for that limited feature.
Earlier on, Nissan had made noise about beginning to charge for the app and/or the CARWINGS service. Many, many posters in this forum said that if that actually happened, they'd just discontinue using the service, given its flakiness. I felt the same. At any rate, Nissan hasn't begun to charge and likely will not, at least not until it becomes far more reliable and useful and there appears to be little appetite at Nissan to make that happen. That's only my opinion of course, worth everything you paid for it.