I've seen a lot of reviews bashing the spare the air policies. I respect that we all may have differing opinions, but SparetheAirBayArea does exactly what it promises: you open it and right at the top it says if it's a spare the air day or not.
What else did you expect this thing to do? Sure it claims to have push notifications, but there hasn't been a STA day since I got SparetheAirBayArea so I can't comment on that. It claims to give the least smoggy bike routes, my experience has it being accurate enough. It lets you report smoking vehicles and see a forecast, but at the end of the day it has only one job: tell me if its an STA day or not!
Now, if you got SparetheAirBayArea thinking there would be a button to change civic policy or thinking that SparetheAirBayArea would allow robust and meaningful discussions surrounding a cost benefit analysis of various region wide air quality interventions, then I'm sorry to be the bearer of bad news. SparetheAirBayArea is to tell you if it's a spare the air day or not. If you want more than that, in all sincerity, please write your senator and convince them to change the policy, not a bad app review to convince people that SparetheAirBayArea doesn't tell you if it's an STA day or not, because it does.