Level 13 is not only passable without paying, it's actually one of the easier levels. Once you develop a solid CC strategy, you'll wonder how it ever stumped you. I'm on level 16 and I haven't been stopped by a timer or used a hammer. The original candy crush had levels that I honestly think were near impossible without paying, but they were much higher numbered levels than the teens.
Me too, im totally stuck at stage 13.. I never really played candy crush much, but never realised I was so terrible at match 3s
Candy Crush Soda Saga I think Soda Saga is a great successor of Candy Crush. Awesome new boosters and many new features. Found a good guide, with Candy Crush Soda Saga Tips and tricks and more. Source: Candy Crush Soda Saga Guide