Open-Source Tools We Built for Our Apps

Building multiple mobile apps teaches you patterns. The same monetization flow, the same ad-to-premium funnel, the same outbound marketing pipeline keeps showing up across projects. Instead of copy-pasting code between repos, we extract these patterns into standalone tools and publish them as open-source packages. The community benefits, we get free bug reports and contributions, and our own apps stay DRY.

The rewarded_ad_counter package, published on pub.dev, solves a common indie developer problem: how do you let free users experience premium features without a hard paywall? Our approach is what we call the "sweat equity" model. Users watch a configurable number of rewarded video ads — say, three — and unlock ad-free access for a set number of days. If they prefer, a one-tap in-app purchase unlocks premium permanently.

The package handles the entire lifecycle: loading and presenting AdMob rewarded videos via google_mobile_ads, managing in-app purchase streams with the official in_app_purchase plugin, persisting unlock state across app restarts using shared_preferences, and rendering ready-made UI widgets that drop into any Flutter app with minimal configuration. It ships with full theme support, localizable strings with interpolation templates, and — critically — zero default ad unit IDs. Developers must provide their own AdMob IDs, eliminating the risk of accidental revenue leakage.

What would normally take hundreds of lines of error-prone glue code — coordinating ad event listeners, billing streams, countdown timers, and reactive UI state — becomes a ten-line widget integration. The package is already in production across several of our apps and handles thousands of ad views monthly.

Most mobile developers believe App Store Optimization and paid advertising are the only acquisition channels. But for vertical B2B apps — property management tools for real estate agencies, dashcam solutions for driving schools — cold outbound outreach directly to business owners can yield far higher conversion rates at virtually zero acquisition cost. That is why we built companies-scraper.

companies-scraper is a Python CLI tool that discovers local business websites by language and geographical region, extracts verified corporate email addresses, and outputs deduplicated contact lists. It supports eight languages, leverages offline geographical data down to the city level for precision targeting, and uses DuckDuckGo search instead of expensive Google APIs. It can decode Cloudflare-obfuscated emails, filter out free webmail addresses, and persist results incrementally so long-running discovery jobs never lose progress.

We use it actively to drive targeted outreach campaigns for My Rents (contacting real estate agencies) and DriveCam (reaching driving schools across the whole world). The tool replaces paid services like Apollo or Hunter.io, saving hundreds of dollars monthly while delivering higher-quality, geo-targeted leads. The full source code is available on GitHub for other developers who need a free, privacy-respecting lead generation engine.

Together, these two projects represent the two pillars of a sustainable indie app business: in-app monetization mechanics and out-of-app user acquisition tooling. rewarded_ad_counter turns free users into revenue without degrading their experience. companies-scraper finds the right users and puts your app in front of them. Both are free, both are open-source, and both are battle-tested across our twelve-app portfolio. We believe in building tools that help ourselves first and the community second — and publishing them so everyone can benefit.