Advancing and Promoting Programming or the APP Act This bill establishes a centralized website to provide information regarding sources of federal funding for the creation of apps (software applications that enable the performance of specific tasks that may be run on a computer, mobile device, or any other electronic device). The website must also allow the public to download publicly available federal government apps. Specifically, the bill requires the General Services Administration (GSA) to establish a publicly available website that includes a database of federal funding opportunities for the creation of apps, options for rating and reviewing apps, tools for app developers, and resources related to education and training in computer science. The GSA shall review any app for which an update has not been released in more than two years and shall remove any app from the website that is no longer functional or compatible.