No, your staff does not have to download anything. They can go to recognizeapp.com from their browser on their desktop or smart phone.
If they want to use Recognize inside Yammer to send recognition or to administer Recognize, they will need to download the browser extension. It is easy to install in the browser and we support a Group Policy so your IT can install the extension across your company's computers.
Contact us to set up a meeting with your IT team to see if we can easily integrate with your company.