To add a dApp to your Bookmarks, visit the website you would like to bookmark and select the icon with the three dots in the top right of the page, then select Bookmark.
Your bookmarks will now appear when tapping on the search bar along with the dApps you have recently connected to.
To remove a dApp from your Bookmarks, navigate to the dApp you would like to remove, click on the icon with the three dots in the top right and select Remove Bookmark. Alternatively, while viewing your bookmarks, you can swipe left to reveal the delete (trash can) icon to remove them.