Hello John,
Your idea is very interesting. I will develop it for you with a price very cheap. By the way, I would like to send you a demo APK for this idea ( a screen password has not been implemented yet, but it doesn't take long time)
If you agree, I will discuss more and complete this app in 1 day on next Monday.
Thank you for read my bidding.
p/s: I will send APK to your mail. Please send me your email and i will mail to you.