It's never a good idea to disable the widget on mobile devices. We find that most leads will come to you via your mobile site and in fact, that's what we built the tool for.
A great way to assess mobile traffic at a glance is to visit your dashboard and scroll down to the devices section.
For the purposes of reporting and browsing behaviour, any changes to the mobile settings will also affect the widget on tablet devices. As you can see from the above chart, that's a huge portion of traffic and usage coming through non-desktop sources.
Configuring Mobile Settings
Go to: Settings > Automated Popup Settings > Mobile Settings
The changes you make in the Desktop Settings will also change the mobile appearance, however you also have the option to disable either the speech bubble or the entire pop-up separately for mobile, as shown below.