How can I download One Touch SDK? Can you send me a link to download in free?
Currently, the only play where the SDK is still available is the project page on the GitHub. The project was created 2 years ago, but the files are still available for downloading.
Access the following link then click on the green button and choose Download. Since you didn't mention anything about GIT sync, this is the proper way to download the DigitalPersona One Touch for Windows SDK.