This is a simple plugin that will not load a sh*t-load of CSS. Instead, the bare minimum stylings are done for the custom theme so that anyone can customize it with their site design.
It is very developer friendly and offers a couple of smart filters and actions to modify default logic (see 
HOOKS.md file).
You can override the custom default theme template to display a tweet by copying the 
/templates/single_tweet.php file and pasting it in your theme 
/templates/lastweets-single_tweet.php folder.
This file will be used to display a tweet; customize it the way you want.
Available hooks
...to be continued...
Built with
Authors
        After installing and activating the plugin, heads to the 
Settings > Lastweets options page.
From there, you can define your Twitter app API keys.
Go to 
https://developer.twitter.com/en/apps to create a Twitter application and retrieve your API keys.