Lettergram is an AI penpal product. Users can send and receive personalized letters through Lettergram. Users only need to write their reply and put it in the return envelope, then send the letter, the AI penpal will automatically reply after receiving it. Lettergram provides multiple virtual characters for users to choose from, each virtual character has its own unique background and personality. Users can choose a virtual character as their penpal according to their preferences and enjoy the interaction with the virtual character. Lettergram's pricing is divided into three packages: Casual, Avid, and Enthusiastic, users can choose the package that best suits their needs.