Google Drive is Google's file sync app that lets you store all of your files online alongside your Google Docs documents, and keep them synced with all of your devices.
Merge requested PDF pages and add the finished file to the request.
Your report or invoice packet is ready on the same spreadsheet row as the source PDFs, with its pages in the order you chose.
Merge linked report PDFs by page order and reply with one file link.
Your teammates get a combined report PDF in their requested page order, with a link back in the email thread.
Merge incoming PDFs in the requested order and share one file link.
Get PDFs merged in the order you list. The folder owner gets a link in chat. You choose where the finished file goes.