What type of website you have? For which you would like to do SEO? Which is your target audience?

There is no website. Its just https://play.google.com. I need some tips about app page optimization.

Hi, I think you should be more specific... please be clear about your query..

Did you ask about Google Play App SEO.
Or how to promote Apps by Google play?

When we want to promote any app in that case we use Google Play Store and add there our App. and promote on Social sites. and your app on Google analytics, just checking your traffic and all..

Sorry for misunderstanding. I asked about Google Play App SEO. I need tips about it. Maybe some details about the way Google rank apps here.

Google app ranking depends on the number of downloads and number of users using that particular app.