Ask HN: Those making $500/month on side projects in 2021 – Show and tell

This page summarizes the projects mentioned and recommended in the original post on

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  • Appwrite - The Open Source Firebase alternative introduces iOS support
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  • SonarQube - Static code analysis for 29 languages.
  • check-if-email-exists

    Check if an email address exists without sending any email, written in Rust.

    I run an open-source [1] email verification API, called Reacher. I managed to hit 10k ARR this year (1st year).

    It's written in Rust, self-hostable, and does not use a DB of emails (like some competitors do).

    Landing page:


  • free-email-forwarding

    The best free email forwarding for custom domains. Visit our website to get started (SMTP server)

    Forward Email is doing several thousand per month now just one year in.


    Open Startup:

  • Appwrite

    Appwrite - The Open Source Firebase alternative introduces iOS support . Appwrite is an open source backend server that helps you build native iOS applications much faster with realtime APIs for authentication, databases, files storage, cloud functions and much more!

  • parsemail

    Hanami fork of

  • Just-Read

    A customizable read mode web extension.

    I made a customizable, feature-packed reader mode that earns around that:

  • inlets

    Get public LoadBalancers on your local Kubernetes clusters

  • awesome-weekly-robotics

    A list of projects that were or will be featured in Weekly Robotics newsletter

    3 years ago I started a newsletter about robotics ( and about month ago I opened it to advertisers and started earning about $600 a month from ads.

  • i18n

    i18n wrapper and Koa middleware for Lad (by ladjs)

    It actually doesn't determine it by the country the request is coming from.

    How it works is fully documented here:

    1) Check URL (e.g. if /de or /de/ then it's a de locale - as long as de is a supported locale)

  • Scout APM

    Less time debugging, more time building. Scout APM allows you to find and fix performance issues with no hassle. Now with error monitoring and external services monitoring, Scout is a developer's best friend when it comes to application development.

  • spamscanner

    Spam Scanner is the best anti-spam, email filtering, and phishing prevention service.

  • inlets-pro

    Secure HTTP and TCP tunnels that just work

  • inletsctl

    Create inlets servers on the top cloud platforms

  • vatcomply

    VATcomply is a free API service for vat number validation, user ip geolocation and foreign exchange rates.

  • AnonAddy

    Anonymous email forwarding

    I use and pay for its also FOSS and can be self hosted.

NOTE: The number of mentions on this list indicates mentions on common posts plus user suggested alternatives. Hence, a higher number means a more popular project.

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