Scroll through the last 3,200 tweets from your timeline (The Twitter API imposes this restriction). Alternatively, import your Twitter archive to view all of your tweets.
Pull down while on the timeline view screen to refresh and view your latest tweets.
Tap and hold any tweet to select it. Select as many tweets as you wish. Then tap the multi-delete button to delete them all at once.
You can delete tweets individually by just swiping to the right
Use the search feature to find unwanted tweets and swipe to delete them. Or you can long press the tweet for bulk delete.
Tap on a tweet to open the detailed view, then tap on the text to open the corresponding tweet in the Twitter mobile app or site.