• Kotlin: “are you talking to me?”

This could be useful. I will add it in the to-do list.

“Tags” are similar to twitter hashtags, you can use them to categorize a post. For example, if you create a post about Android you can add the tag “android” (without “#”). When you manage a magazine you can add one or more tags (always without “#”) to see posts of the fediverse with that tag.
I have no idea about “badges” :)