Check to make sure you have the latest version of Google Play Services and Google Play Store. Old versions may prevent you from getting the latest eBay app.
To get the latest versions, see here:
https://support.google.com/googleplay/answer/9037938?hl=en
More info can be found here:
https://community.ebay.com/t5/Android-App/Android-app-not-supported-on-older-systems/m-p/30652449#M9...
