there's a few Apps that work pretty good. cant remember off the top of my head which I had, but most are adjustable time/sensitivity
this is the one I have. pretty nice.. just sits in the safe now that I dont do IDPA anymore. the apps suck IMOThis is the one I'm currently using and have used off and on for several years:
Amazon.com: Competition Electronics Pocket Pro II Timer Blue [Misc.] [Misc.]: Sports & Outdoors