The iStick includes a USB connector at one end, and an Apple Lightning connector - such as that used by the iPhone 5 - at the other.
A Kickstarter campaign to raise funds has pulled in $765,000 in pledges - more than seven times the amount needed.
Its developer, Sanho Corporation, said in a statement: ‘iStick allows users to easily, quickly and safely transfer data between computers, iPhones, iPads and iPod touches without the need for synchronisation, internet, wireless networks or the Cloud, where hackers and others (like third-party server providers) may gain access.'
The device is expected to be available in August in 8GB, 16GB, 32GB, 64GB and 128GB versions, priced from $129.
A video about the project can be viewed here.