Alternativer til Tinyinvoice.com til Software as a Service (SaaS) med open source-licens

• Software as a Service (SaaS)
  Alle platforme Windows Mac Linux Android iPhone Windows Phone Apple Watch iPad Android Tablet Kindle Fire Web Self-Hosted Software as a Service (SaaS) Slack Electron / Atom Shell Chrome Cloudron
• Open Source-licens
  Enhver licens Gratis licens Open Source-licens Kommerciel licens