There are companies that will drive your "smart" thermostat and purport to save you money by strategically controlling it, but in the end if you want to save money on your house's climate control, you're going to end up being warmer/colder than you would like.
In our last house we had a box attached to the AC compressor that let the utility turn it off for 3 hours at a time, a prescribed number of times per month. We got a $10/month discount for this.