simplayfy is a great way to control iTunes playback. It puts two icons on the menubar, from where you can control iTunes playback almost entirely. simplayfy comes with a great notification system that displays a window in the top-right corner when a song starts playing. The left menubar brings up the search feature, which you can use to search your entire iTunes library without having to switch your current window. The results are shown in a small window that comes down from the menubar. You can click on any of the results to start playing them. The second icon, the one on the right, shows information about the song that is currently playing on iTunes and lets you control playback. This window shows the name of the song, author, album artwork, and buttons to play, pause, and go to the next or previous songs. You can also toggle repeat and shuffle from here and adjust the volume. There is a small button that will bring up the preferences pane. From here you can customize quite a few things, like how long notifications will remain on the screen, and whether you want iTunes to quit and be launched when simplayfy is launched or closed.
In short, simplayfy is a great tool for anyone who uses iTunes on a regular basis. It provides a really easy way to control playback and search for songs without switching from your active app to iTunes.