Once you select one or more elements in the page, the tools panel will be displayed automatically. You can also show the tools panel by clicking the "Tools" button in right toolbar or pressing Ctrl + T (Command + T in Mac OS) even you have not select any element, in this case the tools panel will list some instructions of tool usage.
The actual tools displayed in the tools panel are changing according your current selected element(s). To learn about all available tools, please read Element Reference.
The figure below shows the tools panel and it has several categories:
The categories in the tools panel may vary when you select different element, or select multiple elements. Some categories are common, such as "Current Selection", "Edit", "Position, Size and Stack" etc., they are always there no matter what and how many elements you select. Some categories are dedicated for specific elements, such as the "Text" category is for elements that has text, such as Text Box, Button, Text Edit Box etc.
You can collapse specific category by clicking the icon on the left of category title, then its content will be hidden and it releases some space for other categories.
Memory Usage Information
At the bottom of the tools panel, there is a mini toolbar that displays the current memory usage information.
You can specify the maximum memory usage by clicking the max value ("500 MB" in example above), which will bring you to the corresponding tab in settings window. If ForeUI is running out of memory, try to click the button to see if it can release some memory. If that does not help, you may see a message
When you see this message, it is recommended to save all works and restart ForeUI. If you are editing a complex plot, the default 500 MB memory usage may not be enough. In this case you can raise the maximum memory usage limit to 800 MB or so.