This doesn't address the main point about charging the library for access to clients' recommendations, but, at least in my library's version of Overdrive, it is

This doesn't address the main point about charging the library for access to clients' recommendations, but, at least in my library's version of Overdrive, it is perfectly easy to recommend a book acquisition to my local library. On the page with the search results, there is a "Make a recommendation" link after the results which goes to a page which has all the expected fields - the book ISBN, my name, my home library, etc., etc. Maybe this is a better version than the author has seen? This is not using an app, which I don't know why you would want to do anyway.