Yes. There are many different areas to differentiate on this question.
Any Activity can load a web page right inside Roomie Remote. For instance, one could make an Activity called “Netflix Guide” and then have it load http://movies.netflix.com/. Roomie Remote also supports loading web pages by launching Safari with a specified URL.
Another class of URLs that one might want to load using Roomie Remote are app scheme URLs for other iOS applications. For instance, you might want to launch the Pandora iOS app from Roomie Remote after sending the appropriate commands to your receiver to configure it for playing from your iPhone via AirPlay. Various websites collate information on how to construct such URLs for many applications. These include gadgethacks.com.
Roomie Remote can also be launched back if the launched app supports it via the Roomie Remote URL scheme which is “roomie://”.
From a command perspective, URLs can be loaded silently with no visual presentation of the resulting page. If you have a URL that performs an action, just enter that and mark it as silent.
Both GET and POST HTTP-controlled devices are supported such as Sony Blu-ray players, Panasonic Blu-ray players, older Yamaha receivers, DirecTV, and others. See the IP compatibility list for up to date information on supported devices. The Roomie Remote DDK also provides detailed information on constructing custom command sets for IP control.