A dial measures or tunes, read as adjusting the intensity of something in your life. Dream books link turning it up or down to how much you let in.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.