Sadaqat al-Fitr is due on behalf of every person whose maintenance is your responsibility.

Hazrat Abu Majliz narrates that Hazrat Abdullah bin Umar (may Allah be pleased with them) preferred that Sadaqat-ul-Fitr be given in the form of dates.

Hazrat Ibn Sirin says that Sadaqat al-Fitr can be given from wheat, barley, dates, raisins, and grain. And he expressed doubt regarding flour and sattu. The narrator says that all of these are equal. (One may give Sadaqat al-Fitr from whichever one wishes.)