oh also I'm making black ice tea and it's awesome. Keep in fridge after cooled and you can add various flavors. Lately I add fresh lemon and ginger (while it's hot) (I plan to add fresh fruits next but not in boiling water). I love pre-flavored black teas like mango taste, but those are more expensive and only sold in tea shops here.

Green tea has caffeine too, but usually less. Matcha tea has more since you drink green tea powder.