When you create an order via TradeGecko Mobile you must have a customer to add to that order. Creating a new customer on the go only takes a few mins with the ridiculously good TradeGecko Mobile App.
First, go to the Relationship section of the App.
Touch the New button on the top left hand corner of the page.
Once you've filled out all the details for your new customer, hit "Save" and a new Relationship will be created. That's it, so simple!