Yes, currently the game is still being developed for free by developers on 3 platforms: Android, iOS and PC.

Why is it necessary to top up a Free to play game?

Robux is the main source of finance for in-game payments, an important resource for you to buy and sell paid mini games and rare in-game items. But Robux is not easy to earn and If you want to own a lot of Robux, then you have to pay more money into the game.