What are you looking for in brewing software?

I'm looking for a project to work on to get some use out of my newly minted Apple Developer Membership, so I'm putting out a question to all my fellow home brewers...

What would you be looking for in an iPhone or iPad brewing application? Is there anything missing in current brewing applications that you would like to see? I have some ideas but I really want to develop an application that is widely useful to others than just myself. Any ideas are welcome and although I can't guarantee anything I would gladly welcome people to help test it out as I develop it.

Cheers!

1. Free
2. Can be used for extract or all-grain brews.
3. Has calculations that are tailored to your specific system (i.e., input options such as MLT thermal mass, etc.)
4. Creates one page file of brew day (recipe, required temps, note section) for easy filing (either for printing or saving as pdf.
5. Large database of hops, grains, yeasts and BJCP styles to pick and choose from. But not so restrictive that you can't alter hop AA%, etc.

Check this thread for some ideas:
https://www.homebrewtalk.com/f84/what-users-want-brewing-software-209432/