Tough crowd selling to people looking to cut back I reckon! But I think budget apps are ripe for some breakthrough but the problems to be solved are more wetware issues.
Budget software seems to be based on this idea that you can perfectly allocate all your spending to categories. The more complex your life e.g. partner,
kids, owning cars etc. the more unpredictable things become. And I think the core of it is developing habits > elaborate software that takes time to manage and keep balanced etc.