My landing page is fully implemented. Works nicely on all devices starting from small phones up to 4k monitors.
I didn't publish it yet because I want to finish the app to launch everything together.
BUT what I did meantime was to code a simple "Coming Soon" page connected with a Mailchimp form.
At the moment of writing this, I have 4 subscribers on Mailchimp, not bad for a "Coming Soon" page which has one week old.
I'm #BuildingInPublic on different specialized forums where my audience likes to be, so I hope when I have the app fully completed to have around 20 subs on Mailchimp.