We have a mobile site at m.simpleerb.com which displays a nicely formatted list of your current bookings. You can now also quickly queue bust by adding walkin bookings in this view.
Just click 'add walkin' and it will ask you to select the cover amount and which table you'd like to seat the customer at. That's it. Your customer is in the book!
If you want to go back and add in any customer details later, you can do this on the mobile app or login to the full site and do it from there.