Details
Great app, but the support is MIA at the moment. It seems this app is no longer supported.
Instead try using Visual Workflow, Publisher Actions or maybe try AppShark Lead Conversion for a custom Lead Conversion. Or of course use triggers.
Documentation
I have written extensively about this product
Tips and Tricks https://docs.google.com/document/pub?id=1vC_r0S1SZZEfzgmIxzouZ0M7U9YfLU7RjT5EiDdmWoU
Blog Post http://thedetaildept.com.au/2012/03/25/three-great-free-apps-for-salesforce-admins/
Another Blog Post http://thedetaildept.com.au/2012/12/17/q-and-a-salesforce-custom-button-to-replace-convert-lead-button/