That's really strange that the listing has gone from the OP's purchase history, because the original listing, plus the relisted one is still visible. Original item number 151642190732

OP, to get the eBay app, go to the eBay website on your phone and it should ask you if you want to download the app. If not, go into Play Store. The icon should be on one of your desktop screens on the phone. Tap the Apps button, then type eBay in the search box. It should appear close to, or at the very top of the search results. 

Tap on the eBay option, then when it opens tap on install. It will then install it on your phone. When the download is complete, it will give you the option of opening it. After you've opened it, you'll need to log in. You can also click on the settings option to set up notifications.