I had an idea for something like this, although it would require a bit more up-front effort. Basically, you provide a list of important people, interests, and events in your life, and then the prompts are generated dynamically based on that information. So instead of a prompt like "Write about a time in your life when you struggled with a choice and made the right one," you'd get something like "If you had to take a vacation with [Tom], where would you go and what would you do?" or "When's the last time you went [kayaking]? Do you think [Jake] would want to go with you?" etc.