We recently came across a brilliant online tool called HTTP Referral Testing that allows you to make HTTP requests with completely custom user agents and referral field which allows you to test a range of different scenarios. What makes it stand out is the simplicity of the required information as you don’t even need to actually enter a user agent either, you can simply disclose a referral field and the website you wish to perform the simulation of. Best of all and amazingly, it is completely free to use!
Be sure to check out their great programming section as well which features a range of tutorials in multiple languages showing you exactly how best to take advantage of the website’s offerings. Check them out!