Footnotes are additional information needed for a word or verse but are not part of the text itself. Footnotes are indicated by a blue superscript asterisk icon.
Cross references are links for a word/verse that relate to another word/verse somewhere else in the Bible. Cross references are indicated by a dotted underline.
You can access both footnotes and cross-references by performing a simple tap on the word or icon. Once you see a list of cross reference verses, you can tap on a verse to navigate there in the Bible.