Is a plus symbol without button text sufficient to denote adding of an item?

1. What are the buttons in an app called?
2. Where do I put the help icon?

What are the buttons in an app called?

At their most basic, UX buttons are styled links that grab the user's attention and help drive them in a particular direction. Buttons can link us to other pages or complete an action like submitting a form or making a purchase.

Where do I put the help icon?

A help button, link, or icon relating to the whole form or screen function should be located on the top right corner of the screen but below the global header (see Figure 3). Help relating to the entire application or website, such as phone help, support numbers, or global tips, should be placed in the global header.