How do I identify iOS apps installed from App Stores of different countries / under different Apple IDs?

I live in three countries (Italy, Germany, US) and therefore I'm forced to install apps from different countries e.g. if apps are only available in the local store. For this I use my main Apple ID (US), my mother's German ID and my wife's Italian ID. However, I lost track of my apps associations. I'd like to know this in general, but this is especially problematic when I try to update apps and iOS asks me for "my" password, but I don't know which account it refers to.