Features
Scan Reddit, app reviews and comments for problems to solve
Sources
Six places where people complain in public. For each one Grumbl keeps the text, the date, public counts like upvotes or star rating, and a hashed author ID. It never keeps the author’s handle, never reads private groups or DMs, and never contacts anyone.
Posts and comments in the subreddits where people ask for help and vent.
App Store
1–2★ reviews of the top apps in the niche.
Google Play
1–2★ reviews of the top Android apps.
YouTube
Comments under review and tutorial videos.
TikTok
Comments on short videos about the niche.
Hashtag posts and comments. Lowest signal of the six.
Sources depend on platform rules and can change. Reddit, YouTube and the app stores are the ones with the most signal today. How we handle the authors of public posts
Ranking
Complaints that describe the same problem are grouped, and each group gets a score out of 100. Three inputs do most of the work. Here they are for the top result of the “budgeting app” scan from 26 Oct 2026: 17 different people, 20 mentions across Reddit and Google Play.
- How often it repeatsdistinct people saying the same thing
- How strongly it’s wordedanger, switching, paying to fix it
- Whether anyone fixes itcompetitors named, and how they’re rated
A group needs at least two different people before it becomes an opportunity, so one angry review can’t top the list. The most-requested things nobody has built yet get a higher gap score.
Evidence
Every opportunity opens into the posts behind it: the quote, where it was written, when, and a link to the original. The one-paragraph summary is drafted by an AI model and labelled as such; the quotes are not touched.
“Most apps seem to just show where money was spent rather than what changes would make the biggest difference.”
“Budget didn’t roll over. I have the paid version because I needed my income expenses to roll over but it doesn’t.”
Reports can be exported, and a finished scan can be tracked so a re-run a month later shows what grew and what faded.
What a scan costs
A quick scan reads 500 posts for 5 credits. New accounts get 10.