The APP_ID is stored in the MAIN table, and we need to lookup what application it's for in the APPLICATION table.
The absolute simplest thing to do in SQL, like this:
inner join [dbo].[APPLICATION] app on APPLICATION_ID=APP_ID
But PowerApps just says (meaninglessly, and incorrectly) "This Property Expects Text Values but this propery returns incomptiable record values".
I tried putting "Value" after it; it makes no difference, and surrounding the whole thing with text.
Looked it up online but nothing there worked. Seems like "PowerApps" can't even handle a basic select query, or frankly, anything where joined tables are involved. It only works if you have one big table with everything in.