Having a great app idea is one thin, turning it into a money-making venture is another. In today's landscape, solo founders and tiny teams are building profitable web applications thanks to accessible tech, lean marketing, and relentless focus on real problems.
This report highlights 10 apps earning $10K+ per month, the decisions that led to those milestones, and the sources that prove the revenue stories are as real as the hustle behind them.
Whether you're chasing a side project income stream or the next compact SaaS, these founders show you can build and grow on nights, weekends, or between client gigs as long as you solve a painful problem, launch fast, and keep iterating.
1. ProjectionLab: Personal Finance Planning App
What it is. ProjectionLab is a solo-built web app that helps people simulate retirement, investment, and cash-flow scenarios with beautiful visualizations. Kyle Nolan created it to plan his own finances and slowly opened it to financial planners and families who wanted to experiment with “what if” scenarios.
How it makes money. ProjectionLab runs on subscription plans for planners and families. Nolan bootstrapped it while working full-time, iterating publicly, and shipping customer-driven features. By June 2023 the product hit $10,000 in Monthly Recurring Revenue (MRR), and by mid-2025 it was bringing in roughly $1 million in Annual Recurring Revenue (ARR).
Key success factors.
- Building from a personal itch to ensure there was true demand.
- Treating the project as a steady side hustle rather than chasing shortcuts.
- Iterating on customer feedback and sharing progress publicly to attract the right users.
2. Bank Statement Converter: Fintech Utility
What it is. Bank Statement Converter (BSC) turns PDF bank statements into clean CSV/Excel exports. Angus Cheng built it after banking platforms only supplied PDFs, and he found accountants, founders, and freelancers had the same pain.
How it makes money. BSC monetizes with subscriptions that let customers upload statements, choose formats, and download structured data. Angus focused on SEO content instead of paid ads, and the service surpassed $10K MRR in 2023, reaching about $12K per month by September while he worked on it less than two hours weekly.
Key success factors.
- Picking a “boring” but painful problem people already searched for.
- Lean infrastructure (just hosting + parsing logic) for huge margins.
- Letting satisfied customers compound the MRR while marketing stayed mostly organic.
3. Scrape Creators: Real-Time Scraping API
What it is. Scrape Creators is a usage-based API for scraping public social media data, built by Adrian Horning. He bundled years of scraping experience and his teaching audience into a developer product for marketers, growth teams, and analysts.
How it makes money. Users buy credits to call the API, paying more as their data needs grow. Adrian launched in June 2024, focused on a single product, and hit $10K MRR within 12 months thanks to organic outreach plus programmatic content.
Key success factors.
- Doubling down on one idea and cutting the noise.
- Leveraging an existing audience (students, course takers) for warm leads.
- Personalized outreach plus SEO content for steady, high-value customers.
4. Setter AI – AI Appointment-Setting SaaS
What it is. Setter AI automates lead qualification and calendar booking via SMS and WhatsApp conversations. Josef Büttgen built it during a “12 startups in 12 months” streak and kept the MVP lean.
How it makes money. The SaaS charges businesses by the number of leads processed. Josef shipped in two weeks using existing AI APIs, charged from day one, and grew to $10K MRR roughly 1.5 years later through content marketing, list building, and high-touch sales.
Key success factors.
- Rapid validation with a paid MVP.
- Organic SEO content and nurture campaigns that warmed interested leads.
- Spending early cycles on sales conversations to shape the product.
5. ReplyGuy – Automated Social Media Replies
What it is. ReplyGuy automates replies to Twitter and Reddit mentions. After a slow start as “Replyze,” Alex Belogubov partnered with a marketing co-founder, relaunched on Product Hunt, and rebranded for clarity.
How it makes money. ReplyGuy sells subscription plans (including annual tiers for agencies). The relaunch paid off. Within nine months of the original launch they hit $10K MRR, then sold the asset for a six-figure sum after facing platform challenges.
Key success factors.
- Pairing a builder with a marketer for complementary skills.
- Improving positioning with a new brand, demo, and growth playbook.
- Treating the $300 winter as a learning sprint instead of a failure.
6. Bannerbear: Automated Media Generation API
What it is. Bannerbear is a developer-friendly API that generates personalized images and videos. Jon Yongfook discovered the idea during “12 startups in 12 months” and iterated publicly.
How it makes money. Bannerbear offers tiered subscriptions for teams needing dynamic visuals. After struggling to reach $1K MRR, Jon’s content-heavy focus (blogs, tutorials, docs) pushed revenue past $10K MRR in January 2021 and to ~$52K MRR by late 2023, even as a mostly solo team.
Key success factors.
- Building in public to attract developers and new use cases.
- Shipping integrations (Airtable, Zapier) customers actually asked for.
- Treating documentation as a growth channel rather than an afterthought.
7. Sheet2Site: No-Code Website Builder
What it is. Sheet2Site lets anyone turn a Google Sheet into a working website. Andrey Azimov powered job boards and directories with the product before “no-code” was mainstream.
How it makes money. Running on Gumroad subscriptions, Sheet2Site added features (SSL, payments, templates) while Andrey documented his “Hardcore Year.” By April 2020 he reported $10,069 in monthly revenue with ~87% margins and later sold the app after the milestone.
Key success factors.
- Sharing revenue milestones to build trust and publicity.
- Staying laser-focused on the single promise: side-stepping code.
- Engaging maker communities (Product Hunt, Indie Hackers) for feedback.
8. SiteGPT: AI Q&A Chatbot for Websites
What it is. SiteGPT trains chatbots on your website via GPT embeddings. Bhanu Teja built the MVP in a weekend and pre-primed his Twitter and Product Hunt audiences.
How it makes money. The paid-only launch generated $10K MRR in its first month and climbed to ~$15K MRR within a couple of months, proving that fast execution on a clear AI pain can still beat the copycats.
Key success factors.
- Speed: shipping in days to capture a trend wave.
- Owning distribution (Twitter, Product Hunt) for early adoption.
- Focusing on concrete ROI (instant Q&A) rather than vague AI promises.
9. FormulaBot: AI for Excel/Google Sheets
What it is. FormulaBot turns English prompts into Excel/Sheets formulas. David Bressler launched it in 2022 after decades of spreadsheet frustration.
How it makes money. Individual and team subscriptions fueled FormulaBot’s viral growth. By mid-2023 it was doing around $40K MRR after a Reddit post and freemium model encouraged sharing.
Key success factors.
- Solving a ubiquitous technical pain with clear onboarding.
- Narrowing the focus to formulas instead of a vague AI-assistant.
- Letting word-of-mouth and community trust drive trial-to-paid conversions.
10. Calendesk: SMB Scheduling Software
What it is. Calendesk automates appointments, payments, and reminders for service SMBs. Maciej Cupiał built it after seeing salons, clinics, and gyms still rely on paper calendars.
How it makes money. The B2B SaaS charges monthly by staff/calendars. The product reported ~$9,800 MRR in October 2023 and grew to ~$178K in annual revenue by 2024. This was proof that charging from day one and solving scheduling headaches can scale.
Key success factors.
- Charging early to validate demand and fund iteration.
- Narrowing focus on conversational industries (salons, clinics) that value higher-touch service.
- Compounding local wins through referrals and integrations.
Key Takeaways: How to Make an App That Actually Makes Money
- Solve painful problems. Every app addresses an actual need: automation (Bank Statement Converter, FormulaBot), time savings (ReplyGuy, Calendesk), or enabling new capabilities (Sheet2Site, SiteGPT).
- Validate fast. Many launched MVPs in weeks, took money day one, and iterated with live customers.
- Use the best tools. No-code stacks and AI APIs let solo builders glue services quickly instead of reinventing functionality.
- Start niche. Dedicated audiences made tailoring marketing and messaging easier while building word-of-mouth.
- Grow organically. Founders relied on communities, content, and partnerships rather than expensive ads.
- Persist and iterate. Even the “fast” wins had long journeys; the first $1K MRR is often the hardest, but momentum builds.
- Complementary partnerships help. ReplyGuy proves that adding a marketing co-founder transforms traction, and other founders leaned on advisors or communities for support.
Building a profitable app still requires focus and persistence. But as these founders show, you can hit $10K+ MRR while staying lean and independent. Use their journeys as playbooks, learn from their pivots, and start shipping your own.
Ready to build your own $10K+ app faster? Book a discovery call to validate ideas, prioritize automation, and stay lean while you ship.
