iOS Free wire framing tool for mobile apps

[new-to-mac]

Hi Guys,

I'd like to some wire framing just for personal use and to have a mess around not really to build a commercial app (at least at this stage). I've seen a lot of people use balsamic or azure but these are paid tools and since I'm only doing this for fun I'd really like to start with something free. So after some googling I found

http://www.invisionapp.com
and
http://ninjamock.com/home/index

does anyone have any experience with these tools? would you recommend one over the other or is there a different tool you would suggest?

thanks!

 

[satchmo]

No experience with either of these, but they look good. I'm going to give these a try.
Thanks for the links.