Hi @Alvina!

Posted by: @robert

1. Mark topic as favorite so that user may easily refer later - (in to-do)
2. Add Related Topics - (exists, just use tags to see related topics in topic footer section)
3. Pre ticked checkbox for "subscribe to topic" - (exists, the option is in Settings > Features Tab)
4. Search Topics while typing topic to avoid duplicate topic - (in to-do)
5. Force users to add tags (not planned)
6. Inbuilt notification system so that users will be notified if their topic is replied, liked, voted, answered or commented - (in to-do)

Are 1, 4 and 6 already out? Thank you very much! Awesome plugin.