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

CaseFox - Web-based legal software for law firms and lawyers that has timekeeping, legal billing, expense tracking, time billing, trust accounting, case management, and many more features.

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

SimpleLegal - Modern e-Billing, legal spend, and matter management software for in-house and legal operations. Advanced reporting, automated accruals, invoice management, and more.

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

Legitigant Billing Management - Vanguard I.T. is a technology services company that specializes in helping businesses improve their functionality via technology.