Theres always the potential for "mission creep" with such apps, whilst this sounds like a sensible moral reinforcing device in reality its undermining the personal responsibility of the individual, and over time what might a court demand be added to the list of "warning words" ?
I know this is a negative way to look at things but it seems technology brings out the worst in authoritarian regimes, I expect this app will find great favour in China where if you search for something on the Govt's non-no list they get an email and you get no warning.