If you are on an iPhone or iPad, this is your only safe route. The game will be free. Avoid any "sideloading" tutorials for Ninja Arashi 3, as they often break Apple’s security protocols.

Example steps:

Since you are looking for the free version, here is what you will typically get without paying:

The paid version (usually $2.99 to $4.99) typically removes all ads and gives a starter pack of currency. But for 90% of players, the free experience is more than enough to enjoy the game.