SpellNanny version with free demo of 200 words. SpellNanny paid version is a fun educational app to learn the spelling of 1000 of the most common english words. The approach is to briefly show the word, then you must remember the letter sequence to spell the word correctly. If you get stuck the app can speak the word by tapping the sound icon in top right of the screen.
This is demo allows you to try with 200 words for free with small banner ad.