The KashFlow PHP SDK by Joel Fielder is available to download, found in the tutorial "Integrating with Kashflow using PHP." References explain how to configure the KashFlow account, interact with the API, handle parameters, and create a sales invoice working with the API.
Billing clients and managing invoices and payments is time consuming and probably not the most enjoyable part of running a business. Pancake is a self-hosted online business suite that makes the whole process a lot easier. This application allows users to invoice clients online, manage projects from proposal to completion and more. Pancake provides the Pancake API that allows users to access this functionality through HTML.
Intuit has announced the release of several new resources for developers to integrate desktop applications with web-based applications. The new Intuit App Center allows QuickBooks users to access third party web applications developed with the Intuit Partner Platform. This move effectively bridges Intuit's suite of desktop accounting software with applications that run in the cloud.
Intuit Inc. has announced the release of an updated version of the QuickBooks Online API which is now free to developers to use in building third-party applications. The company also announced the launch of Intuit Apps.com, a new store where users of QuickBooks and QuickBooks Online can find add-on applications that provide added functionality in categories including customer management, billing and invoicing, financial and sales management.