Cashboard - SaaS-based freelance time tracking and invoice software.
ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.
BILLmanager - BILLmanager is an all-in-one web hosting billing software. It provides billing automation, service provisioning, client portal & back office and support center.
MinuteDock - Web-based time tracking software designed to integrate with the Xero accounting package.
Simple Invoices - Never Wait For Clients To Pay You Again!
Elorus - A super-easy online invoicing & time tracking software