DROPitTOme - Allows you to let others securely upload files to your Dropbox account.
Uppy - The next open source file uploader for web browsers
dbinbox - dbinbox makes it easy to send files
tus.io - File Uploads
UploadTo - UploadTo helps to share and receive large files into a Google Drive or Dropbox account without asking uploaders to login
Uppy.io - Next open source file uploader for web browsers