I have been using an Oximeter from Happy Electronics for a few years, and when I read that their newer version had a low oxygen alarm you could set, perfect I though and bought one, but the unit they sent me does nothing more than blink when the oxygen saturation goes below the level I set. Which is totally useless when sleeping! Your application reads oxygen levels, so why not give us the possibility to set the oxygen saturation alarm level ourselves? Power to the users! Anything to avoid wearing an Apnea mask at night time.
Regards
Eric Kavanagh