Throwing a coin into a wishing well is read as hope offered to the unknown. Dream books see it as desire made into a small ritual, and as trust that wishes are heard.
Has this come up in your dreams before? What was going on in your life then?
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.