Whenever you're on the road and needs to create invoice for your client, this apps will able to help you. Just simply hit & go and get the work done.

Quick Invoice bundle App supported PDF format, you are able to make invoice and emailed as attachment. Given you the alternative to print or review via others PDF viewer. This free version will allow you to create the invoice with one item.

The paid version - Quick Invoices provides capability to create instant company logo for your invoice documents; this process will be completed via built-in camera or picking up from photos library. There's enhanced feature - "save/load" contacts details with instant memory or select from phone contacts.
The output from Quick Invoices is coming with PDF format, you're able to : email as attachment, put your own signature via sign pad, print it or view it via others PDF viewer etc. Paid version also supported Dropbox feature to share with others.