Tried app with geiger counter seemed to work,but then tried it with only the software app & it still gave me the same reading,I read something abt u can turn your smart phone into a geiger counter by using camera,so maybe thats why it still works without Geiger plugged in? I wonder did I need to spend that money to have a geiger counter? Well maybe I have a defective geiger counter that's damaged.is part of what's going on.Package arrived on time.And was packaged very nice.It was easy to set up on my android smart phone.the software was easy to find by searching for smart Geiger checker on Google Play Store,look for app that says FT labs on it,there is more than one app can use with it.I had read reviews ahead of time,-so I turned off any internet or Wi-Fi - & turned on Airplane mode.Note when monitoring best to not move phone just set it down before hand on stable place,possibly best in another room & set timer for ten min. & then check reading later to get a more undisturbed reading that would be more accurate,it is sensitive to vibrations & if someone talks by it will make my reading spike to red zone. Comes with Manuel,I read some of the instructions for it,it is so small of script though for me to read very well without magnifying glass or some strong readers but probably most people could read in well lit room.I like that you can take a screen shot of your reading & send it,& record your monitoring history. .note dont move it while taking a reading it will make your reading soar & then it has to readjust again,so found just best to start reading over again rather waiting for it to slowly return to a more accurate CPM reading.Also if you already set everything up right & have it plugged in & it still says to plug it in,(which has happened to me a couple times or more),I then just pushed skip button then it worked .But what works on my version of Android & phone model may not work on yours. You may have a totally different experience with the Geiger Counter & the software then I had.I wonder if I can upload the data Rad readings to a Rad monitoring site.I found one Radiation monitoring site,but they cost like over 2 times as much then I paid for the Geiger counter to buy their software to upload readings to their site to help people.I will keep looking for more sites,or maybe a person could make their own web site for Radiation readings, I guess from reading on the web, that 100 CPM gamma is considered Alert stage,And 300 CPM gamma is considered evacuation stage.