Bitten nails are a familiar sign of nerves, and dream tradition reads them as anxiety or impatience turned inward. They point to worry that is looking for somewhere to go.
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.