This is likely an easy one, but I cannot seem to find the answer. When my users open the Windows Power Apps application they get a large list of apps on the Open page. How do I control or limit that list to be only apps that have been approved for their use by the company?
Could you please share more details about your PowerApps working environment?
Firstly I would ask are you working with PowerApps Desktop Client? Since I found it is not the same as my screen of open apps. PowerApps studio for web is the only choice for production use now as desktop client has been deprecated in June 2018.
Back to your question, PowerApps uses would be able to see all apps created by themselves or shared with them. If you would like to remove a person from the list of shared users, you could go to PowerApps Portal, select Apps on left pane, select an app and choose share on top pane, remove some users or re-add them as User: