No, at this time gantterAi does not offer Apps for mobile devices. 

You are however able to sync gantterAi with your Google calendar. If you have Google Calendar or Google Task on your mobile device, you will see your gantter Task there. You can also access gantterAi from your smart phone or tablet by going to google chrome and accessing your google apps or google drive. 

The bigger the screen the better though. Since gantt charts are horizontal in nature tablets, laptops, and desktops are the preferred devices to use gantterAi on.