Stellar Speller is a utility created for children between the ages of 8-14 to help them practice their English spelling skills. The app features colorful graphics, lets you choose between 5 difficulty levels and various voice profiles, and allows you to select the preferred word category.
This program offers support for the text-to-speech feature. So, every word that needs to be spelled is pronounced correctly by a built-in voice profile. Mac OS X default text-to-speech profile (Alex) is the default dictation voice. You can go to the Apple website to download and install additional voice profiles for free and use them in Stellar Speller.
After you select the proper voice profile and difficulty level, you can start spelling words. If you aren't sure which word was dictated you can always click the Say It Again or Spell It For Me buttons. The latter option doesn't actually skip the current task. It only dictates letter by letter and you need to enter the word by using your keyboard.
Another advantage is that the program gives you access to detailed instructions. So, you shouldn't have any problems explaining your children how the app works.
Furthermore, you can change the background image of the main window and get direct access to the websites of other programs which were created by the same developer, Kenneth Garzo.
In conclusion, I think it's worth installing this free spelling program for your kids.