Adobe InDesign is the second software requirement to use SignAgent Pro™.
All versions of Adobe InDesign CC will work perfectly, including CC 2017. For more info on which versions are compatible, check out this article here: Adobe InDesign Compatibility
You can learn more here: Adobe InDesign
If you need a trial version to get started, you can find that here: InDesign CC 2017 Trial
All versions of Adobe InDesign CC are compatible with SignAgent Pro™. If you do not own a compatible version of InDesign you will need to purchase Adobe InDesign CC.