This expression “Прикольно!” can be translated in English by “It's fun!”. It is one of the most used slang words in modern Russian language. It can be used with different forms like “прикалываться” (to have fun or to make fun of), “приколист” (prankster), “прикол” (a gag), “колоть” (to stab, to kill). It is clear that this word is semantically related to the verbs “шутить” (to joke), “издеваться” (to mock), “смеяться над кем-то” (to laugh at someone).
The following examples give you an idea how to use this expression:
As you see, like its English equivalent, всё может быть прикольно! (everything can be fun!).