XNSPY and mSPY are two of the popular web filters for Android. Having tested them both, I feel XNSPY edges out mSPY due to the extent to which it can filter out sexually explicit results from Android smartphones. During my testing period, mSPY missed a few search terms and wasn't able to filter them out from the search results. With XNSPY, however, I had no issue of this sort. Every key term I had blocked was hidden from the search results, including all variants of it.