I've not used this app but this is definitely possible and has been covered in the literature. The final link is to a paper presented recently which actually pr

I've not used this app but this is definitely possible and has been covered in the literature. The final link is to a paper presented recently which actually proposes using a mobile phone for this. Would be interesting to see what other information can be extracted from optical signals. Tricorders can't be that far off now. http://www.opticsinfobase.org/abstract.cfm?uri=oe-18-10-10762 http://www.opticsinfobase.org/abstract.cfm?uri=oe-18-10-1076... http://vassilios-chouliaras.com/pubs/c51.pdf http://vassilios-chouliaras.com/pubs/c51.pdf http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717852/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717852/ https://embs.papercept.net/conferences/scripts/abstract.pl?ConfID=11&Number=1251 https://embs.papercept.net/conferences/scripts/abstract.pl?C...