Under the iTunes in the Cloud section, click Manage Devices. (If you haven't associated any devices with your Apple ID, you won't see the Manage Devices section.) Information about each associated device appears. Next to each device, you can see when it associated with your Apple ID.
The real reason why the burp smells so badly is hydrogen sulfide (H2S). If you eat foods that have sulfur proteins in them then you may find yourself burping the H2S, which will smell like rotten eggs. The sulfur reducing microbes in the intestine digest the proteins and release the gas.
A sulfur burp is when gas is dispelled from a person's mouth, like a belch, and is accompanied by a strong, foul odor. This odor is similar to the smell of rotting eggs or to the foul smell of sulfur. There are largely three reasons why this condition can arise.