c2c-pipeline is a personal tool used only by its owner, Akilesh Podduturi. It is not offered to anyone else.
The app uses the Gmail gmail.compose permission on the owner's own account to create email drafts and to check that drafts it created exist and have their attachments. It does not read the inbox and it does not send email; the owner reviews and sends each draft.
The sign-in token and related data stay on the owner's own computer. Data is not sold, shared with third parties or used for advertising.