If you're 11 or 12

The three blanks in simpler words:

• Who (one specific person you know, or one specific kind of person your person belongs to)
• What it does (one verb thing your product DOES: finds, writes, tracks, shows, organizes, removes)
• Why they care (the better thing in their life after they use it)

If you can fill all three with words a friend would understand on first read, you're done. If a friend has to ask "wait, what?", one of the blanks is fuzzy. Find which one and rewrite it.