Hi, i see, so many publisher add their adsense in their application. I think yes but there is rules said you can't place adsense in NON content page. how about that?
yes you are allowed to...as long as the content of the Facebook application doesn't violate their Terms of Service (of Google).
You're allowed to use facebook ads. But make sure you contact adsense support before you do this. so they can sort any issues if they face any and won't close your account because of this.