Apps with 'Swiss-army knife tool' feature
With PDFill you can create, fill, delete and submit PDF form fields; insert new formatted text, check, image, hyperlink, whiteout, highlight, drawing, comment and annotation...
File manager / explorer with full access to files on SD card, external SD card, cloud services, SMB, FTP, WebDAV, HTTP, NAS, USB OTG and system internal flash if working on a rooted phone. .
SNIPR software is a leading Credential-Stuffing toolkit supporting attack surfaces like IMAP and HTTP/(s) Web-Requests (Emails, Websites and Apps/Games).