Although you can always open the “My Apps & Games” page on your Xbox One to see all your games, outside the console, there isn’t an easy way to check your games as the Xbox Console Companion app lacks of such feature, and the Xbox app only lists your PC games.
However, if you want to see the list of the digital games you own without powering on your Xbox One, you can perform this task using through your Xbox profile page online.
In the My Games page, you can view all the Xbox One, as well as PC games that you have acquired from the Microsoft Store.
While in the page, you can use the left pane to filter games by platform and department to find games quickly.
Clicking an item will take you to the games page, where you’ll be able to follow the game, check your activity feed, achievements, captures, and more.
The only caveat checking your games online is that you can only view Xbox One and PC games, as Xbox 360 games won’t appear in the list because they’re part of a different system.