I disagree with you Luc, rose apple is in my opinion a wonderful tasting fruit. I think i'm in good company as it has been a revered fruit for thousands of years. For example, t's known to have been a favorite fruit of the Buddha around 600 B.C., along with mangos. The problem with rose apple in Hawaii is that it is/was extremely invasive and weedy, like guava, and also like guava it always gets stung by fruit flies and has maggots inside. I say "was" weedy because the dreaded guava rust, Puccini, loves rose apple and it was the first plant to succumb to it. It's pretty much history for that fruit in Hawaii.
BTW, i'm in land of rose apples right now: India.