A seismograph records tremors, read as sensitivity to shifts others may not yet feel. Tradition links it to an inner alertness to changes in your foundations.
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.