The Mobile Entrée HTTP Modules contain the functionality that allow mobile devices to be redirected to the mobile applications rather than the full fledged SharePoint site. They are activated on a per-web application basis as a web application feature. Mobile Entrée or any apps built using the API will not run on a web app that does not have the HTTP Modules activated.
What devices get redirected to your mobile apps is defined in the
HTTP Filters management page.
Upon installation, Mobile Entrée gives you the option to activate the HTTP Modules for each of your web apps. You may also manage them from Central Administration > Application Management > Manage Web Application Features.