Your post is in regard to the Web App, but it sounds like you mean the Android or iPhone app?

In Android, when I tap the + button, it takes me to the Add Task dialog where I can put in the details of my task. After tapping Save, the task is placed wherever you specify (in a list) or, if not specified, it places it in your default list.

You mentioned that "it shows an event." This leads me to believe I am not understanding your question. If that's the case, please ignore this response.