Spots 
I spend a lot of evenings on TrustMRR looking for my next thing to build. It lists 11,000+ startups with verified revenue, which is exactly what you want when you're hunting for ideas that already make money. It's also exactly how you lose an evening. After a week I had three problems: I couldn't remember what I'd already looked at. Every visit I scrolled past the same cards and re-read them.
I couldn't tell why a boring tool makes $3k a month. The card says MRR and a one-line description. It doesn't say who pays, why they pay, or where the customers come from.
The filters didn't stick, and I couldn't exclude categories. I never want to see mobile apps, but I can only pick categories to include, not hide the ones I don't want. So I built a small Chrome extension for myself. It's called IdeaPanner (pan as in panning for gold).
Mark every card. Hover a startup and you get ✕ Pass · ☆ Later · ◎ Dig in · ✎ Note. Passed startups can be hidden on your next visit, so you only see what's new. The same buttons now also sit under the description on a startup's own page.
Explain. Click ? Explain and an AI writes a plain-language breakdown: what's going on in that market, what hurts, how the product makes money, where its customers come from, whether a solo founder could build it, and where you'd start if you copied it. It reads the startup's public TrustMRR profile, not just the card, so the answer is grounded in the actual numbers.
My list and Compare. Your Later / Dig in startups open in one panel with revenue, your note and the explanation side by side. Switch to Compare and they line up in a table: MRR now, pricing, customer channels, verdict, where to start. It also remembers the MRR on the day you marked something, so you can see what grew since. Hide categories. Pick Mobile Apps (or anything else) and those cards disappear, and stay gone after a refresh. Saved filters. Set up TrustMRR's filters once, save them under a name, restore them with one click. A few things I learned building it
The site is a React app that re-renders a lot. My toolbar kept vanishing after hydration, and some pages use invisible 0×0 links laid over the visible card. The fix was to attach buttons to the visible card instead of the link, and re-attach whenever the page redraws.
Detail pages ship two layouts (mobile and desktop, one hidden with CSS). My first version happily inserted its buttons into the hidden one. Only pick elements that are actually rendered.
Free AI without a server is hard. Asking every new user to go get an API key kills the first click. The new version gives 10 free explanations a day through a tiny endpoint, and falls back to "add your own key" instead of a scary network error if that endpoint is down. Bring your own key (any OpenAI-compatible API) and requests go straight from your browser to that API.
Marks, notes and filters live in your browser. No account, no analytics. The free trial sends the startup's public info to my server, which forwards it to the AI provider; it also sees a random install ID and your IP, used only for the daily limit. It only runs on trustmrr.com, and it's not affiliated with TrustMRR.
I spend a lot of evenings on TrustMRR looking for my next thing to build.