I have seen several talked about. Search the site for Energy Monitor, Energy Monitor Plugs, etc.
Personally, I developed a Device Handler / Smart App for the TP-Link series of plugs and bulbs. For the HS110 Energy Monitor plug, the current useage, plus 7 and 30 day running totals and average are displayed. Could be updated to send to IFTTT.
see thread: TP-Link Bulbs and Plugs Control