Select the app, and then select Uninstall > Uninstall. Scroll down the list and find the app you want to uninstall. It'll take a moment for your apps to appear.
Select the Start > Settings > Apps > Apps & features. Some apps may not be compatible with Windows 11 and can cause a flickering or scrambled screen. If the app didn't come from Microsoft Store, check the manufacturer's site for updates. If the app came from Microsoft Store, check updates for apps from Microsoft Store.