This app is fully functional but has been improved and expanded in our new app Speech Therapy: Practice S

Initial - 10 images with /s/ in the beginning of the word
Medial - 10 images with /s/ in the middle of the word
Final - 10 images with /s/ in the end of the word

Press the speaker icon & say the word. Then select the "check it" button to see if your pronunciation was accurate. When you are ready for the another word, select the "Next" button.

The app uses speech recognition to let you know if your word was accurate so you must be in a semi-quiet environment.