Very good platform to learn Kotlin. I am using Hyperskill to learn Kotlin, with both the web version and the Android application. I especially like "The problem of the day" and the option of being able to review the concepts already seen.

Improvements It's a good learning platform, however there is a bunch of ambiguous questions with unclear answers or questions with wrong andwers in React js where there is said to remove the App.js file.

I so far found it a great platform I recently came across the platform by way of a web search on a technical subject; I decided to read on and explore the site. I'm currently a non-paying member enrolled in the data science study plan. I find the project- (portfolio-) based training constructive as well as the grouping of topics towards a given domain, e.g. data science. I already have a background in Engineering and found the topic coverage suitable and looking forward to complete a project; I will likely become a paying member.

No daily life replenishment The app started out great, it was quirky, fun, and intuitive. I was planning on using this daily. About the 2nd or 3rd day I got a few questions wrong, and eventually spent my daily lives limit. Came back the next day enthusiastic and the lives never replenished! I figured it was a glitch. 3rd day, same result, no more lives. I waited a week and still nothing. So I uninstalled the app

Best platform to learn Java and Kotlin The code reviews help you adopt best coding practices, the integration with IntelliJ is fantastic and I love the way the lessons are written in a concise way, much better than video in my opinion. Oh! and the exercises are great!