I'm the lead developer of CurdBee. Any questions you like to clarify? As you said it is just $5 per month and you can send any number of unbranded invoices to your clients.
There are lot of users enjoying CurdBee PRO add the moment. If you do a Twitter search for `curdbee` you will be able to contact one of those users to know their experiences.
Well, I understand that it does exactly what ClientExec does except cheaper. I mainly work on web design projects and then handle monthly SEO maintenance costs, hosting, and such. My biggest question is, if I switch to your billing platform then will my clients know I'm spending $5/mo on a billing solution? Wouldn't they know by the URL?
Is there a way to mask the URL, or have the application running on my own server where I have full database access?
Also, it appears you've had this around for a while, but why no talk on WHT? Your platform could possibly compete with the other billing solutions that are talked about here on a daily basis.