If you're still growing then there really is no substitute for plenty of exercise and a good diet. Stretching and cycling are always good exercises.
I have seen these websites marketing "growth pills" and I 110% guarantee you that these are all scams. The pills themselves 9 times out of ten are nothing more than glorified multi-vitamin capsules/tablets and are no different to what you can get in places like Holland and Barett at a fraction of the price these unscrupulous criminals are selling at.
Multi-vitamins and protein supplements like L-Lysine, L-Arginine may be useful. In reality these are not magic growth pills like the website is making you believe. Supplements like the ones I have outlined above may help with growth in terms of providing you with allt he ssential vitamins but are not guaranteeed to help.
Anyways if these supplements were the real deal, why is there no scientific research to back up their claims? Most of these websites have no postal address for correspondance, what does that tell you?
If you google the nams of these companies you'll find articles about how they were shut down or how they've been proven to be scams.
If you're young you'll still have time to grow so don't get too down about it. But ignore these websites.