What is the best way to implement a bunch of web plus an android application?

Question

PHP

There is a task to write a website, a simplified version of youdu.ru. You also need to make a mobile application for it. As for the site, everything is more or less clear to me: either pure php or laravel or cms (I look towards Bitrix). I’m thinking about a mobile application, I don’t have much experience in this matter. How to do it better? Webview or a full-fledged application that will take data from a remote server for display, I never wrote rest api.
Please advise how best to proceed.
If Bitrix is ​​used as a back, will it be a problem to write a rest api to its crazy database structure?