While it's cool that specific @mentions will highlight the text in yellow, it can sometimes be a hassle to scroll all the way up through a ton of text to find exactly who's in desperate need of your attention.
No sleep for the weary ....
Enter the Recent Mentions tab. By clicking the '@' logo at the bottom part of the screen, you can view the past 7 days of mentions that included you, with some customization options.
You can tap on the symbol to the top right of the view to open your Filter Options.
From here, you can choose to see @mentions per server or all your servers in one window.
Tap to Jump:
You can tap on one of the messages you have been @mentioned in to jump right to the #text-channel.
To do so, hover over the message you want to jump to, tap on it, and it will automatically send you to the right server and channel. The message you have tapped on will be highlighted.
Now you can keep track of all the letters people have wrote you.