In my Android, when I turn on the screen I see a quick flash pop-up that says: "Network error: it is impossible to connect" (or similar, I am from memory). This is logical as I have manually turn off data usage, but I would like to know which app is writting that message, in order to see if there is any setup to avoid it, or to write author. It is a bit annoyed. Any ideas how can I know which app is it? I have lot of apps.