On Fridays, we take a break from our regular curriculum in spelling and math. In spelling, we play Spelling City games at www.spellingcity.com. The website has free and paid-premium options, however we have always just used the free games.
It is easy to add lists. In fact, at the beginning of the year, I just went through the entire All About Spelling book and made lists for each step (chapter) of the curriculum. Then, each week, it is easy to log in, select the step we just completed that week, and allow the girls to play whichever free games they wish.
In math, we set aside our Singapore books to read a chapter from Life of Fred, and do the problems at the end of each chapter.
Playing games is a fun way to add gifted/talented differentiation to our homeschool planning, and also work on social-emotional skills with my autism kiddo, such as turn taking, manners, and graceful winning/losing.