I adore Lockhart's Ruby Oliver series. Fly on the Wall is the first work by the author not in the Ruby Oliver series I have read. I enjoyed the novel and despite it's brevity, it was well done.
Gretchen Yee is undergoing major changes in her home life and feels lost in her school life. She one day makes a wish to be a fly on the boy's locker room wall and it is magically granted. I enjoyed Gretchen overall but I find the portion where she is an actual fly rather frustrating since it is repetitive and little happens overall. I understand a fly's life must be all this but hearing Gretchen wax poetic about the differences in male bodies is tiresome after a bit. I also had difficulty understanding Gretchen's obsession with seemingly trash-worthy items in her bedroom, another topic she focuses on.
Overall Lockhart's ability to realistically put the teenage experience on paper shines through. Lockhart clearly understands relationships and how individuals speak to one another without needing to ever be over the top. Her characters are vivid and smart and you cannot help but like them. While Gretchen Yee is no Ruby Oliver, she is unique and enjoyable in her own right.