Please note: For the new InvoiceXpress API 2.0, there is a new client available at digfish/ivx-api2-php .
A simple PHP wrapper for making requests with the InvoiceXpress API
Slightly modified, cleaned some redundant code for use with ivxapi Made 'compose'-able with the addition of composer.json
Made slightly corrections since the methods that made use of the HTTP GET command are not using XML anymore.