Are you using the same country and postal code to calculate shipping estimates in both the app and mobile browser as you are using on your desktop?
Can you give an example of a search that returns different results between mobile and desktop?
If you are referring to your own listings, I see 2827 items that ship to my location using a desktop browser. In the eBay app I can see "2800+ results" using the eBay app and 2827 using a mobile browser.
