You've never seen a kid buy condoms because mom and dad are lazy?
I aspire to your lifestyle ;)
kids buy condoms for the same reasons kids used to buy cigarettes or beer. It would be super weird to see the same neighborhood kid buy condoms every week, but it's not particularly alarming on a one-time basis.
Maybe I am just very old, and I should be alarmed by a one-time purchase. I am relating the basic guidelines from my own youth.
It is plainly a bad idea by any standard to provide an application for teenagers to keep diaries of their sexual abuse.