Find what to build
from what people complain about.
People keep writing “I wish there was an app for…” on Reddit, in 1-star reviews and under YouTube videos. Grumbl finds those posts, groups them by problem, and ranks what they want built, with every quote linked.
No card needed. Two quick scans on the house.
- 1Collecting posts and reviews
- 2Dropping noise
- 3Extracting complaints
- 4Grouping and scoring
Top opportunities · 12 found
Budget apps track the past, don’t guide the next month
17 people · 2 sources
People won’t connect their bank account
3 people · 1 source
Paywall before you can try anything
4 people · 2 sources
What one quick scan found for “budgeting app”
26 Oct 2026, US market, 5 credits. 120 posts and reviews read, 76 complaints extracted, 12 opportunities ranked. These are the top three, unedited except for the headline.
Budget apps track the past, don’t guide the next month
17 people · 20 mentions · Reddit 14, Google Play 6
Budgeting apps focus on historical tracking rather than giving actionable guidance and flexible categories. AI-generated summary
“Most apps seem to just show where money was spent rather than what changes would make the biggest difference.”
People won’t connect their bank account
3 people · 3 mentions · Reddit 3
Privacy-conscious users avoid budgeting tools that require direct access to their bank accounts. AI-generated summary
“The whole “connect your bank account” thing is what keeps me off most budgeting apps, feels invasive for something that’s just basic math.”
Paywall before you can try anything
4 people · 4 mentions · Reddit 1, Google Play 3
Users are blocked from testing core features or basic functionality without paying high subscription fees. AI-generated summary
“Won’t let you enter pretty much anything meaningful nor use it in any meaningful way before pushing you to pay.”
Summaries are drafted by an AI model and labelled as such. The quotes, counts and links are the data. How the score is built
How a scan works. Three steps, no dashboards to learn.
Pick a niche
Type a few keywords and the markets you care about. That’s the whole setup.
the six sources Grumbl scans →Grumbl reads the complaints
Reddit threads, 1-star reviews, YouTube and TikTok comments, cleaned and grouped by the problem people describe.
every idea links to the posts behind it →Read the ranked list
Each opportunity has a score, the people who asked for it, and their words. A quick scan costs 5 credits.
what a scan costs →What Grumbl is not
So you don’t buy credits for the wrong reasons.
- Not a trend database. It doesn’t tell you what’s growing on Google. It tells you what people are stuck on this month, with the posts to prove it.
- Not a curated idea catalogue like IdeaBrowser. You bring the niche; Grumbl brings the evidence.
- Not a review-reply tool. It reads reviews to find what to build next, not to manage an app you already run.
- It never shows who wrote a post. Author handles are hashed on arrival. How we treat authors of public posts
Your next app is already being requested.
Run a scan on the niche you know best and see what people would pay to have fixed.