I believe this is possible with the iPhone version too.
But I cannot decide on which minute the agitations are supposed to occur. I can get it to agitate every 30s, or every 3m. No problem. It's just that the app tells me I should be agitating at, for example, the 7 minute mark, while I need it to be on the 8 minute mark.
Here's a layout of my HP5+ process:
At -11m15s, pour in chemistry.
Agitate full first minute from -11m to -10m
Agitate 10s every 2m, at -8m, -6m, -4m, and -2m
At -15s, pour out chemistry.
Hang to dry.
The app forces agitations at the 9m, 7m, 5m, 3m, and 1m marks. I want to change that to the above, but I can't.