The document exists somewhere. There is a download, a scan in a note and a copy you edited last week. A tidier file setup starts with knowing which one is the working original and which one is ready to send. Three apps can play different roles here: a file home, a PDF workbench and a place for quick capture.
“Must-have” means a shortlist for this paperwork situation, not a universal ranking. You may need only one role. The useful result is a file you can find and hand off, rather than three new places in which to lose it.
Documents: give files a deliberate home
Documents by Readdle is a candidate for keeping downloads and selected cloud folders together. Its Store listing describes file organisation, archive extraction and document tools, with a free download and purchases. Start with one folder for one job rather than importing every drive you own.
The sync guide describes syncing connected cloud folders to make local copies available offline and sending changes when connectivity returns. Seeing a file in a connected cloud location is not the same as preparing its local copy. Read the Documents review if working away from a network is central to your day.
Give the working file a name that survives outside the app: topic, date and a meaningful version. Decide which location owns it. A cloud copy, an offline copy and an outgoing attachment should have an understandable relationship.
PDF Expert: work on the document
PDF Expert is the PDF-specific candidate when the file needs more than a new folder. Its official listing describes annotation, form filling and signatures, with editing and other advanced tools behind Premium. Choose the tier by the job you perform repeatedly, not by the length of the tool list.
