Please stop spreading that non-sense! First off, you do not have to enable any "Home Sharing" in order to copy around apps! That alone shows that you do not know what you're talking about. I
can simply grab the app binary from one computer, copy it to the other, import it on the other device - done! No need to enable "Home Sharing" (which indeed serves a complete different purpose, see my other post).
Well, expect that it does not work -
IF the app properly would evaluate the "store receipt", which I guess many many developers simply do not care about investing additional effort (or might even be unaware of that requirement).
The fact that you managed to use apps purchased with one Apple ID and
run it on another device with a different Apple ID only shows that the
developers of that (presumingly cheap) app did not implement this:
https://developer.apple.com/library...ral/ValidateAppStoreReceipt/Introduction.html
Believe me, that "receipt validation" is not trivial, especially since you need to think about "hiding" that functionality in your binary (even Apple recommends to write your own validation code and not use a common "validation library" - otherwise if one app gets hacked, it would be trivial to hack any other app by reverse-engineering the binary code - but I won't bore you with details here...). That is the reason why many many 0.99$ apps probably can be "freely" (
illegally, off course) copied around and used with
different Apple IDs.