@oqouoq: There is only a website that works well on all screen sizes. If you're uncomfortable with using it on a phone, you can go to https://www.similarworlds.com on your computer. An app is in development for people who do prefer using a phone, but the website will remain in use too.
@FeetAreFantastic: liking and other reactions are already listed in the development plans. Following posts is already possible by clicking the "Receive notifications" button near the top.
@Darlingrose: The team is actively working on improving the maturity filters. That process takes time, but the situation should improve gradually.