It is only apps that were downloaded from the App Store that can show up on other devices that use the same Apple Account and are the ones showing at Settings > [name on top] after scrolling to the bottom. Your PC laptop is showing up there because you have signed into an Apple Service on that device, but there is no App Store there that would allow a downloaded app to show up on your iPhone. On your iPhone, you can prevent an app from showing up from a download in the App Store on another Apple device by going to Settings > Apps > App Store > App Downloads, and toggle that switch off.
In a Family Sharing group that uses Purchases Sharing, every family member has access to an app that was downloaded from another member. I'm not sure if those apps show up automatically on other members device, but I don't think so. I may be wrong or there may be a Setting in family sharing that will allow that.
Purchase Sharing
Your PC did not download an app on your phone. You can put data into iCloud on your PC such as Photos and they will show up on your Phone, but apps cannot be added to iCloud where they would show up on your Home Screen of an iPhone.
It is fine to have your PC and Roku TV showing as logged into your account at Settings > [name on top]. That is the location to look for all devices that are signed into your account. I should have been more clear when I told you that devices listed there can add apps to your phone, and specifically I meant Apple devices that have downloaded apps from the App Store where you have allowed them to be added to your phone at Settings > Apps > App Store > App Downloads.
