Drawdown-protected custom FIRE portfolios with API for rebalance alerts
Make.com integration is convenient, but Personal Capital and TradingView already handle portfolio alerts.

Yet another alert service, but at least it's Rust and actually ships.
Skiers, hikers, and travelers in Western US mountain regions
511.org · Caltrans QuickMap · RoadNow
I got the idea for this product after fumbling with the Caltrans Highway Status page last March while Skiing up in the Sierras. It was pretty painful to get updates from the realtime highway status. Now I found some time to ship a solution (in Rust no less, if that matters to you).
Hope you enjoy getting email alerts for highway closures in the lighest web app I could reasonably build.
Make.com integration is convenient, but Personal Capital and TradingView already handle portfolio alerts.
No-account email alerts for FDA pet food recalls beat manual database checking.
Price tracker for AirPods, but CamelCamelCamel and Keepa already do this better.
Amazon restock tracker, but limited to one niche product category.
Amazon restock monitor for Pokémon cards, but CamelCamelCamel does this already.
Yet another price tracker, but only for RTX cards on Amazon.