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.
Penny - Penny is a personal finance app that takes the pain out of keeping track of your finances.
ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.
RevOps Cashflow API - Automate your closed-won operation with low-code and no-code
Elorus - A super-easy online invoicing & time tracking software
Term Optimization - Reduce churn, boost LTV, drive cashflow