AnyAudio is a platform where you can download and preview any song you can think of. You my either browse songs or search the one you wish to listen to.
The technology stack consists of
Android SDK (that's all, if I'm not missing something). As of now (January 15, 2017), the project is hosted on Openshift.
We primarily scrape YouTube to present data to user. That is the reason why I said that we can provide you any song you ask for. Apart from on-demand data collection, we also run periodic tasks to get trending content from YouTube.
The disk space requirement to run the server is very low, owing to the fact that we keep only the media that is required. Out of the 1GB of disk space provided on Openshift, we hardly ever used more than 25MB for media files. Talking of things other than disk space, we easily handled more than 3500 requests per day (Jan 2017) with 512 MB of RAM and a single core CPU.
Update: The server is now open source -