portainer/app/components/footer/statusbar.html

<footer class="center well">
    <p>
        <small>Docker API Version: <strong>{{ apiVersion }}</strong> UI Version: <strong>{{ uiVersion }}</strong> <a
                class="pull-right" href="https://github.com/crosbymichael/dockerui">dockerui</a></small>
    </p>
</footer>