You can search for Delete Pages In Pdf app on iOS app store. Furthermore, you can do it online of PDFfiller.com - A Free Solution to all your PDF Problems . I hope , your problem will be solved in these two ways.
If you open an output file in Google Chrome browser, it may appear that the files are not created on your actual machine or that they are not in the correct directory. To avoid that, you can move or rename your original file to be used as output file. After the PDF files have been split, you can use “Save” tool to automatically create a new PDF document (if you saved your original document previously).