A metal detector is read as searching for something valuable hidden beneath the surface. Dream books link it to curiosity and to uncovering forgotten parts of yourself.
Where in your waking life have you met something like this lately?
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.