How to SEO web applications without text content?

Question

I know that google indexes web pages by the keywords found in the content.
I've tried to SEO my recent web application https://dcbotting.com

Proper tags are used. Meta tags are done. Sitemap exists and submitted to google search console.

Of course google matches my site when you google search "dcbotting.com".
Is there any better way to get my site to match for keywords?
There's no need or space to add a lot of text content that googlebot requires.

And can someone explain how google displays the additional pages like this?
https://gyazo.com/5e6f7211d055e980fc7e54ee7d0f5a84

Answer 1

1) I recommend using as many keywords on your main page as possible

No need to add extra content just try to push in as many relavent keywords as possible

Ex: Site is about planes. Thus put as many plane names and maybe flight names. As a result Google will most likely show your content

2) Those are sub-sitemaps that you also need to submit to Google.
MAKE SURE YOU LINK YOUR SUB-SITEMAPS TO YOUR MAIN SITEMAP(very important step)

Hope that answers your question