The program has the ability to create ability scores based on either the Standard, Classic or Heoric settings as per the pathfinder rule book. The reroll 1's is an addition feature used as a house rule in my gaming group.
Character advancement is used to determine the XP for next level based off the characters current level.
Each world may have a variety of "common" languages, so I provide an default option for when a common language is selected, that the program prompts for the choice of common language.
Fractional progression was introduced in Unearthed Arcana. It uses a system that for each class base save, it is broken down into fractions, so that multi-class characters may gain a increase slightly earlier when two fractions add up. I have included this as we still use this rule at my gaming group from time to time.
The last option was introduced to allow users to compare different characters option quickly staying on the same section rather then defaulting back to the first - Race & Attributes.