Scammed into making a purchase

I started the 5k program but cant finish it without making a $3.99 purchase in week 2. I feel scammed into making a purchase because I wasnt informed of the purchase when I started it...maybe its in the fine print somewhere but who reads that?!?! There are better totally free running apps out there.

Luisa671guam about Running Trainer: 5K Runner, v2.3