- Startups.fyi
- Posts
- $15K/Month Party Rental Tool, AI Bookkeeping That Pays for Itself, and a Prediction Market Tool Following the Smart Money
$15K/Month Party Rental Tool, AI Bookkeeping That Pays for Itself, and a Prediction Market Tool Following the Smart Money
Chris Bulen & Daniel Ebohon
June 09, 2026
Hi everyone 👋
It’s Chris & Daniel, from Startups.fyi.
Welcome back to another edition — where we highlight real founders quietly building, shipping, and earning from tools they originally built for themselves.
If this email was forwarded to you, you can subscribe for free and get instant access to all past editions.
We’d love to hear from you—if there’s anything you'd like us to cover, just reach out on X and say hi! 👋🏾.
Alright, let’s jump into this week’s discoveries 👇
Startups FYI Spotlight
📊 Smart Traders Uses This Tool
If you've ever traded on Polymarket and wondered how the top performers always seem to be a step ahead, this tool is built for exactly that. It tracks the most profitable traders in real time so you can follow the smart money instead of guessing. (Pre-revenue)
🛡️ AI-powered Threat Detection Tool
Matt(the founder) got fed up with bots sliding into his DMs on Facebook, TikTok, and Instagram. So with a little help from Grok, he built an AI-powered threat detection suite that scans URLs for phishing, analyses images for spoofing, and maps threats in real time. It started as a personal fix. Now it's a full enterprise-grade platform. (Pre-revenue)
🗂️ One Place for Clients, Projects, Files, and Conversations
If you're managing client work and your files, your messages, and your bookings are all separate, a founder built a tool to solve this because he was living that exact nightmare at his own studio. It's a clean workspace that brings projects, files, conversations, and bookings into one place. (Generating $100 MRR)
🔥 Need a Developer Fast?
Hiring the right developer can take months and cost a fortune. This easy-to-use tool cuts through that. It matches startups with pre-vetted remote developers and gets them in front of you within 72 hours. If the hire doesn't work out in the first two weeks, you don't pay.(Generating $300 MRR)
Our best startup stories are below!
Customer.io is the customer engagement platform for tech-savvy marketers.
Trigger email, push, in-app, SMS, webhooks, and more, all powered by real-time product and behavioral data. Build sophisticated journeys with branching logic, run experiments quickly, and iterate without constant engineering lift.
Thousands of founders rely on Customer.io for onboarding, activation, and lifecycle messaging. Join the Customer.io Startup Program and get up to 12 months free.
🧾 Your AI Bookkeeper
This founder built a simple AI tool for bookkeeping. You connect your email, and the AI finds all your receipts, puts it in one place and organises your money automatically. With no spreadsheet, by the end of the month, your books are ready to use. (Generating $3,000 MRR for the founding team)
🎉 Rental Management Tool
Here is a rental management tool built by people who run a bounce house rental business. It started as an internal system for deliveries, schedule changes, and payments. The team later turned it into a product for other rental businesses. (Generating $15,000 MRR for the founding team)
—Let’s get YOUR startup listed!
👉 Use this link to share your project with 15,729 startup founders, entrepreneurs and indie makers.
Startups FYI Roundup
⚒ The Quiet Goldmine of “Boring” Tool Websites
No fancy app. No team. No VC pitch deck. Just a handful of AI agents, one solid master prompt, and a business model that has been quietly generating consistent income for over two decades. While everyone chases the next big thing, these simple tool websites keep running in the background.
🚀 He Ran an AI SEO Agency for 3 Years. Then Raised $21M to Replace It.
Thenuka and Shravan spent three years running an AI-powered SEO agency and quietly turned their entire playbook into a product. Sunbeam is an autonomous SEO agent that handles everything an SEO team would — start to finish. Backed by $21M, they're betting one AI agent can do what most startups pay a whole department for.
💻 How to Build a Team of AI Agents
If your AI setup is just the same prompt running in different tabs, it is not a team. A real multi-agent system only works when each agent has a clear role and a clean way to hand off tasks. Here is a breakdown of all 9 stages from a single agent to a production crew that actually delivers.
(Tag @ChrisBulen to get your project featured in next week’s roundup)
Advertise with us!
Promote your product in our newsletter and reach over 15,729 of the most ambitious and inspiring startup founders and indie makers on the planet.
That’s it for this time! See you again next week.
— Chris (@ChrisBulen)