In simple words
Type any name and Vesper turns its letters into numbers. You get three numbers: Expression (your talents), Soul urge (what your heart wants) and Personality (how others see you).
Tap a number to read its meaning. For your own reading, use the full name on your birth certificate.
How it works
In the Pythagorean system, the letters A to Z are numbered 1 to 9 in turn, so A, J and S are 1; B, K and T are 2; and so on to I and R, which are 9. Each word of the name is added up and reduced, then the words are added together and reduced again to a single digit, keeping the master numbers 11, 22 and 33 whole.
The expression number uses every letter. The soul urge uses only the vowels, the quieter inner voice of the name. The personality number uses only the consonants, the outer layer that people meet first. Y counts as a vowel when it carries a vowel sound, as in Lynn.
The Chaldean system, an older method, gives letters values from 1 to 8 by sound rather than order and reads the compound total before it is reduced. Vesper shows both, because traditions differ and the comparison is interesting in itself.
Using it well
Use the birth name for a personal reading, since that is the name the tradition reads. For a business, a pen name or a username, check how the expression number sits beside your own: a 1 suits something you want to lead, a 6 something built on care, an 8 something meant to grow. A number is a lens, not a verdict, so let it start a conversation rather than settle one.