The best cause to appreciate a foam roller might be running.
Massaging out tight muscles with a foam roller is a pleasurable activity to do after your running session. They vary in range and length but I think all of them can work at the time of stiffness. I got mine from Decathlon and it was the cheapest option and it still works great. Just wanted to share this little tip with you as an amateur and beginner runner. In case of you are a beginner and decide to run like me, it might work as a reminder.
There are many videos on youtube about how to use a foam roller for your different body parts. You may go with them or enjoy your foam roller freely 🙂