Is there a way to draw a box around a star in order to read the peak pixel value? Right now, I have to zoom in greatly and sweep the "finger" over each pixel to sample it.
So the Windows and Mac versions will have the star profile viewer by default, the Linux version might or might not depending on your system packages. The Star profile viewer depends upon a fairly new QT module called Qt Data Visualization.
And yes AstroNerd, there is KStars on Windows and Mac. KDE programs are built in QT so they are cross platform and they are ported using a tool called craft.