As a music teacher I have experienced some difficulties with new beginners about learning the music notes. It is often complicated for them to remember the names of the notes, where they are located in the note system, the relationship between keys and notes, and which key they should play when there is a key signature before a note. 

F and G keys are located on a single note system. "Piano Helper" is supposed to be pasted directly on the keyboard keys like stickers and can be removed easily after use.  

"Piano Helper" has received positive response from music schools and private individuals in Norway and other countries.