You can open a PDF in PDF Expert, then add, delete, and rearrange pages, or move pages from one PDF to another.
Add a new page
Tap the Pages button > Edit >
Tap on the Pages button > Edit > select one page or several pages > Delete on the upper toolbar
Navigate to the Pages button > Edit > Tap and hold on a page thumbnail > drag the page to the place where you want it to be.
Tap the Pages
Note: PDF Expert allows rotating pages with two fingers as well. Just tap and hold with two fingers on the page thumbnail and rotate it.
Extract pages from a document
Tap Pages button > Edit > select a page or pages > tap Extract on the upper toolbar > save a new file by tapping Done in the Save pages as a popup
Tap Pages button > Edit > select a page or pages > Actions button > Extract.