Say it once. Skip the form. It's fantastic.
An event starts as a sentence. "Dentist next Thursday at ten." "Standup every weekday at nine." "Rent, last day of the month." You already have the whole thing in your head, in order, done.
Then most calendar apps make you take it apart. Title in this box. Tap the date field. Spin a time wheel. Open a second screen labeled "Repeat" and hunt for the right radio button. You arrive knowing exactly what you meant and leave having filled out a form about it. KashCal just reads the sentence.