To "like" a video on Clash, tap the heart-shaped ❤️ icon, or simply double-tap anywhere on the screen. 
Whenever you like a video on Clash, the Creator will receive a notification on their device. This can also be a great way to get other Creators to notice your own work!

All of the videos you have liked can be viewed by going to your profile page and tapping on "likes"
You will now see all the videos you have ever liked on Clash.
(Please note that any other user who looks at your profile can also see what videos you have liked)