Bobplum providing you have custys email address you can email an invoice using
www.aworka.com which would work just the same as your suggestion.
Lee no i did not have any input into Aworka but when you sign in to Aworka you have the option to leave feedback or post suggestions that other people can vote on and chris will update his response on Aworka or twitter when new fuctions are in the pipeline .
Such as the time off function for instance which he expects to get up and running in time for Xmas with a lot of people been off at the same time .
And why cant you just use text or email on your phone to send pics and price jobs surely to intergrate it into a mobile app it would be a big job and would possibly not get used that much anyway which would be a waste of time and money in the development process .

Mike