Media center app maker Plex introduced a new app for Windows and Mac OS Thursday that comes with some significant changes to its support for desktop PCs. Most notably, Plex is phasing out support for Home Theater PC (HTPC) setups. Plex’s new desptop app also replaces the company’s dedicated Windows Store app, and introduces a new framework for downloading media for offline consumption that will ultimately find its way to its mobile apps as well. Finally, the app also comes with the company’s newly-refreshed user interface, which introduces a navigation sidebar. However, the decision to end support for HTPCs  is likely going to be the most controversial among Plex’s user base. “It marks the end of an era for us, and we’d be lying if we said it wasn’t a little bittersweet,” the Plex team wrote in a blog post. For the uninitiated, HTPCs are dedicated PCs connected to TVs or projectors to access streaming services and downloadable media. This used to be the primary way for early adopters to bring digital media to their TV screens, and apps like Plex owe much of their early popularity to this use case. In fact, Plex, XMBC / Kodi and Boxee all gained significant traction after Microso...