Power Tools are combinations of markup types with user defined colors that trigger special functionality like citation lookups and table recognition. Power Tools are therefore a handy way of speeding up research tasks you do often in Highlights.
Tap the More-button in the toolbar to bring up the document settings:
Scroll down to the Power Tools section:
Find the desired function and tap on the circle on the right hand side of the markup type to bring out the color picker:
Here is an example of what the section can look like when all the power tools are set:
When a color is set for a power tool, any annotation you add with this markup type and color will automatically trigger the functionality defined here.
In other words, with the above settings, if you underline a citation with the purple color like this:
This will trigger a citation lookup and if successful your note will be updated with a citation without any additional steps:
Similarly, if you make an image selection over a table using green (with the above settings):
Table recognition will be triggered and if successful your image will be replaced with a table without any additional steps:
Keep in mind that power tools work for both new and existing annotations in the PDF, so the colors chosen should not conflict those used for regular annotations.