I was on ebay through mobile browser yesterday and it showed me an offer to download and pay through the app, if I did so I could use a £10 voucher. I can't find that code now.
Try this page and see if it'sat the top: Summary | Myebay | eBay. Failing that, try going to checkout and see if the notification scrolls across at the bottom before you pay. I always find it a real faff to locate these vouchers when you switch to the app.
