You could use Font Awesome with bootstrap, it includes classes for some neat icons and also classes to make them spin; http://fontawesome.io/examples/ see "Animated Icons"
Implementing that .btn-spin yourself wouldn't be too hard either, couple lines of CSS...
in bs3, there was no easy way, you had to basically use javascript to achieve it.
<button class="btn btn-default btn-spin">Click Me</button>
I been waiting for something like this to be achievable for some time now.
Bulma has this perfected and it really is handy.