Around 15% of total traffic that goes trough Sellfy powered checkout pages are people using mobile devices. As this number is large enough (and growing) we have added mobile checkout support. This will be especially useful for smartphone users as they have the smallest screens.
This update goes out for all our merchants and no additional changes on client side are needed. However we encourage our merchants to make sure your site is optimized for mobile traffic as well. These 15% of people using mobile devices are coming form your sites!
Here are couple screenshots how checkout process looks on iPhone: