Question on using Samsung Tablet Tab 4 with Android app

If the specs at Galaxy Tab 4 10.1 SM-T530NU Support & Manual | Samsung Business are right, that's an ancient version of Android it has: 4.4. I found Samsung Galaxy Tab 4 10.1 - Wikipedia mentions Android 5.x.x.

We're up to Android 11 now (Android version history - Wikipedia). My work-provided Pixel 3 is on Android 11.

Someone else will have to chime in what unofficial Android releases might work on it.

My suggestion is to pick up an 8th gen iPad 10.2" when they're in stock at $299 or less (Today's Cheap iPad Deals on New and Closeout Models). Apple at least releases iOS/iPadOS updates for their latest products for awhile. That said, IMHO, neither the Android (I have it running an old Nexus 9, which got dead-ended long ago) nor iOS version (running on an iPhone 8 and iPad Pro 10.5") of TiVo's app are very good.

Back to Apple support, for example, per https://everyi.com/by-capability/maximum-supported-ios-version-for-ipod-iphone-ipad.html, iPad (original) Air ended at iOS 12.x. It came out Oct 22, 2013. iOS 13 came out mid-Sept 2019, which the iPad Air couldn't be upgraded to. So, effectively it hit a dead end that at that point. However, somewhat oddly, Apple has continued to put out various mostly small security updates afterward w/the latest being 12.5.1 in Jan 2021: iOS 12 - Wikipedia.