Most useful I would describe as 'wheels come off if we stop using'. Ours are: - Quickbooks Online (backoffice/finance) - Smartsheet (work management/collaboration/file sharing) - Amazon AWS (hosting infrastructure)

Other services I subscribe to and find work well are: - Zoomerang (online surveys) - MyEmma (e-mail marketing) - GoToMeeting (web conferencing) - Jott (voice capture and transcription, integrated with Smartsheet)