As there are over 70 phonograms, we do not teach all of them explicitly in the current program. We do introduce a few at a time to ensure ample exposure and practice. This approach allows young children to master the sounds in order of frequency, including those with only one sound, without feeling overwhelmed.
Also, additional phonograms that are not in the Learn to Read section of the program are included in our spelling program, Hooked on Spelling (also included in your App purchase, and Practice Packs are available).
Once children come in contact with more challenging phonograms, including those with more than one sound, they will have the foundational skills to decode a new word, continuing to build fluency with this skill.
Please do contact us with additional questions around this subject, we're here to help.