Sickness

[froggyboy604]

I imagine some more advance air filters may come with apps which remind you to replace the filter.

[Skeithex]

They can, but I don't like adding extra 3rd party stuff to wifi, can bog down the bandwidth.

[froggyboy604]

I think some air filters may come with a simple Month calendar which you can manually set by rolling a cylinder to dusplay what month you changed the air filter.