sp - the 8th in our "focus" series! (aa, uu, ff, au, rr, ao, rl, sp & th). Spiral radiuses. Expanding out and contracting in. Timing is key. Just like other apps in our series, the more you get into each level, the more it changes. There are theoretically infinite ways you can complete each, it makes for great fun. You can also top the leaderboard and earn medals!