There are a ton of piano apps for phones but if you want to get down keyboard style while on your computer, check out Virtual Piano, the keyboard for your keyboard.
This website features, well, a virtual piano. You don’t need to know how to play piano to enjoy it, however. Although the notes and the sound they make are real, the keys of the piano correspond to your keyboard. In order to help you play songs, there are music sheets written in letters. So really, you just have to know how to type.
Every letter and number on your keyboard matches a key on the piano. Hold the shift button to access the black keys. This website won’t really teach you how to play the piano but it will let you mess around with music for a little while which can be very relaxing. Virtual Piano is a free site and has a ton of music sheets in both classical and modern hits ready to play.