Ruby Redfort, Look Into My Eyes is the first book in the Ruby Redfort series.
"Meet thirteen year old American girl Ruby Redfort. She may seem like any other all-American girl, but she is a genius. At the age of eight, she made up a code that even Harvard professors struggled to crack. That's why when mysterious voices leave messages on her phone, and a fly symbol keeps popping up, it doesn't take Ruby too long to discover Spectrum."
-Extract from theguardian.com. Click the link to read the whole thing.