BastasTools currently contains the following:

AutoMath:

Automatically calculates the answers to math expressions found in chat messages. You can calculate math expressions locally with the /math command. Parses expressions while correctly handling order of operations and parenthesis.  Some functions included such as sin,cos,tan,asin,acos,atan,log,log10,etc.

ElvUI Frame Highlights

Set-up custom buffs/debuff highlighting when using ElvUI raid frames. By default this addon is set up to highlight frames with debuffs relevant to healing Mythic Antorus, the Burning Throne.

Silent Mute

Silently ignore messages sent by certain players or messages containing certain keywords/phrases. A log of recently-blocked messages is available so you don't accidentally miss something important.

Voidform Translator

When a shadow priest and another user are both using this addon in a raid group, messages sent from voidform will be readable. Due to current API limitations this only works for chat messages and not the chat bubbles over a player's head.

Talent Reminders

Setup reminders for gear and talents to use on current raid bosses. If you reach a boss without an item equipped or a talent selected, you will get a popup reminder on what to change. You can dismiss this reminder, or swap things around until it goes away.