I have one invite only script but when I log in 3 android devices with same ID... I can use that invite only script on all three devices..
How I can restrict it for only one device?
I don't believe you can limit use to one device but one ID.
If your concern is about someone sharing their account, they certainly wouldn't do it with a live trading account because whoever they shared it with would have access to that person's trading capital
Is there another reason you would like to restrict it to one device?
Yes I have created a script that shows buy and sell signals. I want it to sell on monthly subscription. My concern is if someone took subscription from me and shared that id with another people then? And also If live account is not associated with it then he can share. That is why I want to restrict it to one device.
I feel you... I wouldn't worry too much though, as (1) very frequently traders know any other active traders so they shouldn't share. (2) if you restrict your access to only people with paid accounts, people will be more reluctant to give an ID/PASSWORD to someone if they are paying for it, (3) if they are live trading, they would certainly not share because the other person would have access to their real trading money. (4) stealers are gonna steal, so I decided not to worry about it and just provide a good service with good value.