def summarise_app(app):
    """Return a string the summarises the important information about the app"""
    state = app["state"]
    if state != "Installed":
        state = state.upper()

    pin_status = "Pinned" if app["is_pinned"] else "NOT PINNED"

    known_status = "UNKNOWN" if app["application_version"]["is_unknown"] else "Known"

    return f"{state}, {pin_status}, {known_status}"