I really like Close.io; everything less-technical sales reps/etc need from a CRM (principally it plays really well with Gmail so even if they don't live in the

I really like Close.io; everything less-technical sales reps/etc need from a CRM (principally it plays really well with Gmail so even if they don't live in the app your business can pretend that they do) plus a really powerful API for integrating deep into your app/email toolchain/Slack channel/etc.