A few notes that might persuade you differently.
- Building cross app relationships is basically the same as Merging the applications.
- Every time you load one application, you have to load the other too.
- Users will need to have access to both applications (or at least viewing privileges) in order to see the drop-down or company name.
- That makes managing users a bit of a pain.
- Moving / Copying tables to a different app will break all relationships.
- If you are trying to create a master companies table because you want multiple business processes apply to one company, I'd recommend building 'under/within' the current app, rather trying to move things.
- If you have to move things to a different app, I'd prepare your data migration plan before hand.
- Last suggestion, is to look into a QB to QB sync table. You could sync the companies to a different app and then build the new process there.