1. Aircall
2. Call Box
3. CallRail Inc.
4. CloudTalk
5. ConnectAndSell
6. Dialpad Inc.
7. Elastic Inc.
8. Groove
9. Gryphon Networks Corp. by ManTech International Corporation
10. HubSpot Inc.
11. Kixie PowerCall & SMS
12. OpenPhone Technologies Inc.
13. Revenue.io
14. Salesloft Inc.
15. VanillaSoft
16. ZoomInfo SalesOS