Alternativer til Tinyinvoice.com til Slack med kommerciel licens

• Slack
  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
• Kommerciel licens
  Enhver licens Gratis licens Open Source-licens Kommerciel licens