What tools do you use to streamline your field service?

One of my startups has a small field service part. So, I'm wondering what tools do you use to boost the productivity, better track performance, and avoid lost revenues? For now, we use Planadoapp.com for scheduling tasks and tracking everything, and bundle it with Zapier.com and Google Sheets to automate data collection and filling out our CRM.

Do we miss something cool here?