What&#x27;s wrong with that? It&#x27;s commercial software, and they are nice enough to let you use a copy for free. They aren&#x27;t (AFAIK) doing anything remotely malicious, like grabbing user data or bundling malware. It doesn&#x27;t add advertising to your computer.<p>(I&#x27;m not sure if f.lux does any update checking, which some people might count as unacceptable)