Tenshield app for iPhone and iPad

Tenshield releases a large number of negative ions, which are
particularly good at removing pollen, mold spores, bacteria, and
viruses from the air, as well as dust, pet dander, and cigarette
smoke. Negative ions attach themselves in large quantities to
positively charged particles, negatively charging them and making them
too heavy to stay airborne, preventing them from entering your
breathing tube.
Clean air is essential for a healthy life. Air pollution is one of the
most serious environmental threats to human health. Getting an
efficient air purifier or steriliser is one of the surest ways to
eliminate all sources of pollution, enhance indoor air quality and
improve air security. We may not be able to see it, but our indoor air
contains harmful levels of invisible particles that cause serious
physical and mental illness.