Age appropriate to introduce alphabet to 2.5 year old

This app has taught my busy 2.5 year old how to recognize letters. Great starting point in my opinion. We only use it for short periods of time, not even every day. Only has capital letters, but he has started pointing them out in books and on clothes and says their sounds. Recommended age of 4+ is overstated as my 2.5 year old can easily navigate the app.

Workin.girl.needs.2.sleep about Endless Alphabet