If you want to leave a comment on another user’s post, follow the following steps:
1. Tap other user post on NanoFeeds or their profile
2. It will redirect you to post details image
3. Find typing bar with the text “Share your thoughts”
4. Click on the typing bar
5. It will open up the keyboard
6. Click + button if you want to insert image and ticker
7. After writing all the characters you can send the comment by clicking the send button (represented by a paper plane icon).