No. The Tracyapp is a web app. That means you do not need to download a special app from the App Store or Play Store. 

iPhone and new Android devices: 

Open the camera app and point the camera at the barcode 

The camera detects the QR Code and asks if the link should be opened with your standard browser app

Confirm the opening

Now you can enter your contact details in the web form and send it

On older Android devices it may be necessary to download and use one of the many free QR Code Scan Apps available.