Sudoku is traditionally read as the need for logic and order in a crowded mind. Getting stuck on one can mirror a situation where every option seems to block another.
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.