I tried all of that. Including Fusioninvoice, Rocketinvoice, Pancakeapp, redmine, mantis, Zoho, BambooInvoice, SugarCRM and OpenERP and many little invoice tool

I tried all of that. Including Fusioninvoice, Rocketinvoice, Pancakeapp, redmine, mantis, Zoho, BambooInvoice, SugarCRM and OpenERP and many little invoice tool, but none of them offers such great UX and UI. The workflow here is rocksolid. I didn't know of: buggenie, bugify, bugkick. Fusioninvoice is nice, but buggy and targets ONE language only, that English. (Why don't people think about i18n and l10n from the beginning, when designing something that's going to be used internationally.)