Do you need this or does the camera work as a stand alone?

Hi, if you have Lollipop Baby Camera and you need temperature/humidity/air quality sensor, you could buy Lollipop Sensor. Lollipop Sensor only works with Lollipop Camera and it could not work as a standalone device. Thank you.

Will this detect poor air quality in a house that people have smoke cigarettes in?

Sort of. It detects air quality and you can set your own range what is acceptable.

When will the lollipop camera be back in stock? Purchased this sensor along with the camera and amazon cancelled the camera, but not the sensor...

Dear Customer, Thank you for your email. For your information, Lollipop camera will be back on Amazon in mid-September. If you couldn't wait till that long, you may be able to purchase the camera from our official website and shipping to US. Here’s the link: https://store.lollipop.camera/ Sorry for the inconvenience and thank you for your understanding. Sincerely, Daniel from Lollipop Team

Does the sensor detect smoke and/or co2? What exactly does it mean by "air quality"?

Dear Customer, Thank you for reaching out to us. The air quality sensor we use for monitoring is called VOC sensor (Volatile organic compounds) which is use to detect the presence such as acetone, heptanes, and many other metabolic products, in human breath in addition to formaldehyde, cooking odors, human bio-effluents, outdoor pollutants, paint and lacquers, cleaning supplies and toxins. The mixed gases/VOCs are often released into a facility's air from building materials, furnishings, office equipment and adhesive. A simple realization of the air quality of our VOCs sensor detects not only how it feels but also by how it smells. So when it is shown that the air quality is poor, it might be caused by many different reasons. You can try to verifying the reasons by determines is there any smells of cooking or cleaning. If is in that condition, then should be no harm to human’s health. Hope this information will be helpful for you. Sincerely, Lollipop Team