Your OneShot Golf account can only be used on one device at a time. To move your account to a new device, first make sure it is associated with your email address on your old device. You can confirm this by visiting the profile screen and completing the sign up process. If the process is already complete you will see your email address at the top.
On your new device, install and open the OneShot Golf app. Visit the profile screen and select "I already have an account" to enter your email address and move your account over."