Almost all textbooks and dictionaries use their own transcription key, I haven't come across plain old IPA in language learning textbooks, only in linguistics textbooks.
IPA was in use in every German high school book for English or French in the 1980s. I have no reason to believe it has changed, but I haven't used any since then.
Using own systems I have seen in very naive tourist guides and in text books by English speaking publishers.
