I'm working on a trip planner for vegans. This is designed to solve my particular problem as a full time (vegan) nomad who likes to stay in walkable cities.
I noticed that sometimes, I book accommodations in a new city without realizing I'm very far from the nearest vegan restaurant, having to walk for a really long time to get food, and sometimes getting there after the kitchen is already closed.
The planner helps me find hotels/airbnbs that are within 15 minute walk of at least 3 different vegan restaurants - makes my life so much easier!