I love the Lonely Planet guides, but I don't like the budgeting that comes with them. I'd quite like an app into which you could say "I have a budget of $THIS_MUCH, plus or minus $THAT_MUCH for the day. I am in $LOCATION and I would like to experience $THESE_SORTS_OF_FUN_THINGS. Please generate, perhaps pseudo-randomly, an itinerary of fun for the next $NUMBER of hours with all that in mind".

One of my favorite things to do is explore a foreign city with a recent Lonely Plant book to guide me. I think there’s something fantastic about that experience that can’t be replicated by an app or website.

When I’m traveling one cool tech thing I’d like is an AI assistant that could actually place calls in any language to book hotels, tickets, or just check operating hours for places I find in the guidebook.