the author of this app says:
pSoundex is a tool for Genealogists. Give it a surname and it displays the corresponding soundex code. Using it, you can assign a number to a person's last name. The number is such that last names that sound alike get assigned the same number. The genealogist can take his/her palm to the genealogy library and compute the soundex code for a name before looking in an index that is based on soundex codes.