Hey there-- I work at Nylas.<p>We&#x27;ve structured our business to... actually have a business. Our team spent the first year selling APIs to developers [1] which already power lots of paid apps. The N1 mail app we released two months ago[2] follows this and will have paid features next year.<p>Plus both are open source free software, and quite popular on GitHub. [3]<p>[1] <a href="https:&#x2F;&#x2F;nylas.com&#x2F;features&#x2F;" rel="nofollow">https:&#x2F;&#x2F;nylas.com&#x2F;features&#x2F;</a><p>[2] <a href="https:&#x2F;&#x2F;nylas.com&#x2F;n1" rel="nofollow">https:&#x2F;&#x2F;nylas.com&#x2F;n1</a><p>[3] <a href="http:&#x2F;&#x2F;github.com&#x2F;nylas&#x2F;" rel="nofollow">http:&#x2F;&#x2F;github.com&#x2F;nylas&#x2F;</a>