Where does Bungie authorize the use of this app? I'm hesitant to use my credentials in these situations.

All this time I thought the Dead End Cure 2.1 armor WAS the Dead Orbit armor!

There was a stupid Destiny site for Exotics, I forgot the name of it: they claim to track your Exotics and show how many you have of what, the stuff that's left, all that junk; and of course you had to make an account. But it turns out you had to check off each Exotic manually. Equally useless!

I came across another one of these sites the other day over on the subreddit. It is called Light.gg
Without trying it out, it looked like a pretty good little tool.

I'm not really on board with 3rd party tools that require authorization from my account credentials. To my knowledge I haven't really used one yet and don't have a plan to start using one. I'm hoping that Bungie will provide their in game/in application 1st party release solution sooner rather than later.
After basically scrapping 3 years of collecting progress in Destiny 1 and then declaring Destiny 2 a "collection game" prior to providing the basic tools in game for collecting, it is down right low. It is like putting the proverbial cart before the horse. To compound it, there are items that are collectible, but out of reach beyond a soft pay wall, and will be going away forever after an unprovided timegate/date on the calendar? Frustrating beyond belief.

I was not truly involved with collecting in Destiny 1 until Bungie themselves made it a rewarded focus during Rise of Iron and Age of Triumph with the addition of in game 'books' that tracked progress. Don't get me wrong I was involved with saving cool unique weapons, special armor sets, event specific things, and some mission items/consumables that I liked. And I had a Vault space that was jam packed and difficult to manage. However I was not concerned barely at all with vendor sold Emblems, Ships, Shaders, Sparrows, Exotics, etc until there were active book nodes for them (The various in game kiosks were a god-send). That is when my pre-existing inner monster was released.
With the exception of unique Emblems, I don't care much for personalization options. These items were more or less personalization items and were basically inconsequential to me at that time.
All around I am a bit of a completionist/perfectionist when it comes to gaming, at times cripplingly so. Enough that sometimes I cannot start and just play to enjoy a game without a paranoia that I might be missing progress/achievement/item/etc. Or I will barely start a game and get side tracked and then never actually finish it. I've always been a secret hunter and a careful player but I think this evolved to a new level with Xbox Achievements.