Is eBay app update bypassing Apple's app store screening? On iPad, the ebay app keeps popping up a screen asking me to update.  No updates have shown available in the app store for a long time.   Is this a way to get around Apple's vetting process and give me undocumented "features" that Apple won't allow?  Apparently, not, but why/how does IOS not show that an update is available?

iPad IOS is generally updated within a day or two of new release.  Currently at IOS 9.0.1, with update screen showing up-to-date.

Have never done a jail-break.

App Store "purchased" screen says version 3.6.0 for eBay.  App store update screen does not offer an update for ebay.  App store description (from search) shows version 4.0 available for download.  But IOS notifications do not show update available.

eBay app on launch always says "The new app is here" with an "update now" button in a large pop-up titled "Message from eBay"
Current version of the eBay app is 4.0 - requires iOS 7.0 or higher.

Unless your iPad is Jailbroken, all apps come from the iTunes app store.

If iTunes isn't offering the update, maybe either your iTunes or iOS is out of date?