Here is a compact air purifier that cleans the air of viruses, smoke, allergens, and other harmful particles. The FitAir can clean the air within a 25 square feet area. It has a max air flow of 130 L/min. The battery lasts up to 6 hours. The FitAir connects to your smartphone via Bluetooth. Its app shows you the air quality around you at all times.
This air purifier measures 2.9 x 2.9 x 2.6″. It is available for under $100 at this time.