I apologize, because between OP’s post and looking at the OnlyOffice website, I got the impression that it was only a web app, requiring a web server to run. After reading another comment here I looked harder on the website and found the download links for the standalone versions.
Almost everyone in this thread is talking about wannabe tryhards, investment, and reliable watches, but for people who are interested in the pictured watch, they’re real, but pretty cheap and flimsy; I have a couple.
They came out in gashapon machines a couple of years ago, although I got mine just last year for (IIRC) ¥500 a pop. It’s a series by Takara-Tomy with two models of Saturn (black and white), and two models of PS1 (PSX and PSOne).
https://dlmag.com/playstation-1-and-sega-saturn-themed-watches-for-classic-game-fans/
https://www.piggygaga.com/shop/gashapon-sega-saturn-playstation-vs-watch-collection/