Make existing solution cross-platform compatible

Hello, Here is what I am looking for Background: We have a web application that allows a user to upload or download a file directly from or to a USB drive using jnlp (java web start). The jnlp automatically detects the USB drive and the file upload/download does not require any human intervention. Problem Statement: We want this web application to run on an iPad and jnlp doesn't work on iOS platforms! Desired Solution: You will need to figure out what it would take to give the users a seamless experience on an iPad while still allowing direct file downloads to USB drive. We do not want the users to manually download files and move them to the USB drive. Also, we do not intend to build native apps at this time. There are multiple possibilities 1. Change the web application to detect the operating system and use something else in place of jnlp to achieve the same desired result. 2. Research an existing off the shelf offering that can be used as-is or in conjunction with another solution. Next Steps: Unfortunately we can't make the web application available to you. However, the use case is straightforward. You may want to first create a quick solution that simulates the web application and then use it as a baseline to experiment against. If you need more details please reach out to me and we can talk.