In the following lines of text I'll share my opinion about this app, LetterSchool, and write down the things I like and dislike about it.

Pros:

• simple and intuitive UI
• it helps young kids learn writing
• it has both Capital and Small letters
• multiple fonts to use
• it has both letters and numbers

Cons:

• nothing

Developing games for children that actually help them learning new things is rare, and this one is a good one, it's visible by it's number of downloads 1 mil. +

Great hunt @deanliu!