Ciao a tutti, in versione desktop ho creato questa lista, che appare cosi

Schermata 2016-09-02 alle 10.53.55.jpg

codice:
<div class="list-group">
                                    <a href="#" class="list-group-item">sdfsd<span class="badge">145</span>
                                    </a>
                                    <a href="#" class="list-group-item active">sdfsdf<span class="badge">50</span>
                                    </a>
                                    <a href="#" class="list-group-item">sdfsdf<span class="badge">8</span>
                                    </a>
                                    <a href="#" class="list-group-item">sfsdfsf<span class="badge">25</span>
                                    </a>
                                    <a href="#" class="list-group-item">sdfsdfsd<span class="badge">145</span>
                                    </a>
                                    <a href="#" class="list-group-item">sdfsdfsd<span class="badge">50</span>
                                    </a>
                                                                     </div>
come faccio a fare in modo che in mobile diventi dropdown?