If you use the online, Austiblox version, then yes, it is multiplayer. Austiblox supports full-on multiplayer where you can play with other people around the globe.
If you want to use the local multiplayer version, download Novetus. Then inside of the Novetus application, under (I think) Server IP, change the localhost value to your IP (ONLY IF YOU ARE HOSTING IT ON YOUR LAPTOP/DESKTOP) if you aren't hosting it and a friend or relative is hosting, re-enter the localhost value then press the PLAY button on Novetus DO NOT PLAY PRESS SOLO FOR MULTIPLAYER
Hope this helps!