There are a lot of threads on here about this. Between BeerAlchemy, iBrewmaster, and (for iPhone) BrewPal, it really just comes down to personal preference. All have similar functionality, and it's tough to quantify their different UI design choices.
For me, BeerAlchemy's interface was annoying enough that I stopped using it even though I really liked the fact that it syncs with Macs. Others report loving BeerAlchemy. I'm not sure what you mean by stitching a few iPhone screens together, but I've liked iBrewmaster's interface better than anything else out there (which is not to say that it couldn't be better).