Open source first

A calendar that publishes posts to more than 30 social networks: X, LinkedIn, Instagram, TikTok, YouTube, Reddit, Bluesky, Discord and others. The whole code is open source, so anyone can run it on their own server for free; the company sells the hosted version from US$29 a month. Since 2025 AI agents such as Claude, ChatGPT and OpenClaw can connect to it through an MCP server, a command-line tool and a public API, so an agent drafts and schedules the posts and a person approves them in the calendar.

The founder took a twenty-year-old product category with no open-source entry and open-sourced all of it, which gave him millions of Docker downloads and 37,000 GitHub stars without a marketing budget. Revenue stayed small for a year. It multiplied when he turned the product toward people who automate their posting with n8n workflows and, from late 2025, with AI agents, which need an API-first scheduler and keep paying because they post without human effort.

One API address, in the same format as OpenAI's API, that forwards each request to one of more than 200 models from more than 40 providers, such as OpenAI, Anthropic and Google, and records the cost of each request. Customers prepay credits at the providers' prices plus a 5% fee, bring their own provider keys for free, or run the open-source code on their own servers. DevPass is a monthly subscription for AI coding agents.

Every team that builds with AI models ends up with several provider accounts, keys, invoices and SDKs. One gateway with open code replaces them, and a developer can read the code before sending traffic through the hosted version. In 2026 the founders added DevPass, a flat monthly price for coding agents with an allowance of up to three times the price in model usage. The verified monthly receipts grew from US$57,994 in January 2026 to US$249,922 in August 2026; TrustMRR does not split them by product.

A web app that turns a screenshot, a mockup, a Figma design or a screen recording of a website into front-end code: HTML with Tailwind or CSS, React, Vue, Bootstrap or Ionic. The code is open source under the MIT licence and free to run with your own model keys. The hosted version at screenshottocode.com sells monthly credits, so the user needs no API key and no setup.

The founder released it as a free open-source tool nine days after he wrote that the new GPT-4 Vision and Turbo API previews allowed only 100 requests a day. Hacker News and GitHub trending brought the repository more than 35,000 stars in under three months, and the README sends readers on to the paid hosted version for people who do not want to set up keys and servers. It had made US$1,000 within 19 days, with a Stripe payment link and no user accounts.

Three small AI web apps from one founder, run beside his full-time job. Questgen turns text, PDFs, web pages, images or videos into quizzes (multiple choice, true/false, fill in the blank) and exports them in the file formats that school learning systems import. Supermeme.ai, built with two co-founders, turns a sentence into memes: it finds fitting meme templates and writes the captions. AiArtist.io, the newest, makes short motion-graphics videos from text.

Questgen started as free open-source code on GitHub whose README sends readers to questgen.ai, where the paid plans are. Both apps then won search traffic for exact phrases such as "AI meme generator", and Supermeme says it has spent nothing to acquire its users. Costs are low: in June 2022 the founder said his two products were profitable at US$500 and US$100 a month. So a part-time team with no investors can keep them running.