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.
What causes sulfur burps? Most burps smell like the food that caused them or the current contents of the stomach. A sulfur burp is simply a burp accompanied by a foul rotten egg smell. This smell is that of hydrogen sulfide (H2S) gas. Sulfur burps are typically caused by one of the following: