Free system generates an SSL on your domain name and forwards it to popular domain sales services.
If someone wants to buy your .app domain name they won’t be able to use Whois to contact you. Google Registry does not show .app domain owner information in Whois.
That means you have to park the domain name so people can fill out a contact form to inquire about buying the domain. That’s not easy, either; the domain name you have must have an SSL certificate installed in order to forward to another page.
A domain investor created a simple and free tool to make forwarding domains to landing pages possible: DomainSales.app.
The system is very basic but does just what you need it to. When you submit a domain and point your nameservers to it, it gets a free LetsEncyrpt SSL certificate for your domain. You can then choose to forward the domain to landing pages for many different services: Afternic, Epik, Efty, Sedo, Undeveloped, and Uniregistry as of today.
To see it in action, visit Voicemail.app.