Approach would be along the lines of using a door sensor and then after it being open for X amount of time to then either turn off the Ecobee or raise it's set cooling point. Few things you'll have to tinker with; the amount of time for it to be open before it takes action (you don't want this thing to constantly be sending commands to your AC), the action on the ecobee side (turning it off might not be a good idea, adjusting the temp will work better), and lastly, the whole thing backwards; when door closes, resume previous operation. All this should be able to be done in the new app. I have a similar setup but am using WebCore so I know for a fact it's possible there. Some of the commands available to you from the ecobee will also depend on how you have integrated the Ecobee in your system, i. e; is it the Smartthings integration or are you using a custom handler?