BillGrid.com - BillGrid is an easy to use online invoicing, billing and expense management system that will save you time with tracking clients projects, expenses, invoices and payments.

MinuteDock - Web-based time tracking software designed to integrate with the Xero accounting package.

ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.

Elorus - A super-easy online invoicing & time tracking software

fusebill - Fusebill is the leading recurring billing and subscription management software for businesses. Try Fusebill for subscription billing made easy!

Street Invoice - Mobile Invoicing for Android, Blackberry and Windows PC