The best!

This is the best iPhone implementation of our favourite HP 12C calculator! Not only does it have all the features of the 12C, it also smartened it up with what a modern smartphone can offer with extra display info and conveniences. The pricing is also just right. Although I also have HP’s 15C port on my iPhone and use that for the various mundane calculations in a simplified portrait format, this one from Stone Meadow Development is my go-to for anything above that. No regret for the purchase from quite a while back and the support has been fantastic, now iOS7 updated. Can’t recommend enough!

OzHeart about Calculator12 RPN, v3.5.0