Here is the full list of all 10 Moving Letters achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Arrange a word "Apple"
Arrange a 9 letter word
Make 10 words
Arrange 5 words
The letters make up words
Drag and drop the any letter
Play online mode
Play 5 times online
Arrange a word in the last minute
Arrange a word "Spider"