S.A.M Studios has explained things but I thought I would poop back to clarify things personally.
The app does
NOT update the game. That isn't what it's for. The app is used to collect all of the new and changed files from a recently updated version of the game, made by the official NLT Media updater, and packages them into the smallest update possible to take the game from one version to the next version: it's a tool that can be used by
people who use the official NLT Media Updater to update their games, by downloading files from NLT Media servers, to make smaller "update only" updates for others. Step 1 in the instructions how to use the app should have made this clear, i.e., "Update The Symphony of the Serpent
using the NLT installer/updater." If you run the app without updating your game using the NLT Media Updater all that happens is you copy files from your game to a zip file and, if you use that update to update your game, copy them all back to your game back to you game again which changes their timestamps and nothing else.
I'm hoping that a particularly generous Grand Master supporter of NLT Media, who can update their games using the official NLT Media updater, might consider using the app to make minimal updates and upload them for us after they update their game locally. I suggest that we keep our fingers crossed that such a "hero" might step up, come forward, and do the do.