I am looking to build an app with a simple upload function that allows users to select files from there phone and upload them to my dropbox folder with my own GUI and without the dropbox upload and confirmation screens. Do I need access to the API or is there another work around? Thanks!
Dropbox does offer an API you can use for uploading and downloading files, among other operations. The API was designed with the intention that each user would link their own Dropbox account though, in order to interact with their own files. It is technically possible to connect to just one account like you describe, but we don't recommend doing so, for various technical and security reasons.