The concept behind the Hello Music website is a simple but brilliant one: provide members with information regarding all manner of deals and sales, on all kinds of musical goodies. The Hello Music app does pretty much the same thing, only on iOS. In other words, with an account on the website and the app on a phone, anyone looking for great deals is covered.
The site, and by extension the application, will per-negotiate discounts on a set (and limited) quantity of various items. These range from tangible objects such as amps, pedals and such, to less tangible things like studio time. Since quantities are limited the deals don't last long (usually around 48 hours), but with a handy-dandy iOS app to monitor these deals on the go it becomes much less of an issue.