As of writing, the NVIDIA App is still being distributed as a standalone application. You get it from the NVIDIA website here. Installation takes a couple of clicks.
At first launch, you are greeted with a dialog where you select your preferred driver type. NVIDIA hands out two kinds of drivers for its GeForce hardware—Game Ready drivers targeting gamers, and Studio drivers targeting creators. You can switch between the two driver types at any time. The main difference between the two is the optimizations NVIDIA puts out with each release. Game Ready is a monthly (or sometimes bi-monthly) package timed with important game releases. The Studio drivers are quarterly (sometimes monthly) packages timed with the release of new creator applications or new features in those applications. These include game optimizations, too, but not as quickly as you want them if you're mainly gaming on your PC.
The next screen in the dialog lets you get NVIDIA App to automatically detect and apply optimal settings for all detected games. This is similar to what GeForce Experience does, and NVIDIA App carries over the game settings optimization tech over from the older utility. I found the default "enabled" checkbox to be in a rather unexpected location and people who just click "next... next" will miss it, and it will change the settings of all their apps and games, possibly in unexpected ways. Two separate buttons "yes," "no" would be the more honest choice I think.
The next screen lets you enable the NVIDIA Overlay, a persistent utility that you can bring up with Alt+Z (configurable), which gives you quick access to important settings, tools, and system monitoring in game. Same issue here, it's hard to spot that clicking on "Done" is actually "Yes, enable the Overlay."
Under the Hood
Once installed, the NVIDIA App shows up in your Start menu as simply "NVIDIA"—not "NVIDIA app," which could be slightly confusing to some less experienced users.
In the NVIDIA system tray icon context menu, the naming is written correctly, and it lets you launch NVIDIA App and the classic NVIDIA Control Panel.
When it first came out in February, we thought NVIDIA App was a Windows modern UI (UWP) application, but digging into Task Manager reveals that it is actually a CEF (Chrome Embedded Framework) application. The NVIDIA App encapsulates a miniaturized version of the Google Chrome web-browser, and NVIDIA App is actually an HTML-based application (just like WhatsApp Desktop or the Twitter/X desktop app).
Launching the NVIDIA App will actually start five processes that consume around 150 MB. This is in addition to the backend services for the app, which are running as "nvcontainer.exe," consuming another 60 MB. When clicking the X, the "NVIDIA app.exe" processes will all shut down, but the "nvcontainer.exe" processes will be running at all times. Overall memory consumption is quite reasonable.
The screenshot on the right shows a system without NVIDIA App installed, to confirm that "NVDisplay.Container" is running at all times, even without NVIDIA App.