In my case, that's literally true. I use my own website (see signature) on my Kindle Fire while playing (much as the OP does with the iPad - not because I'm on x-box, I just like being able to actually scroll through my ingredients while using my site), so I designed it to work well with tablet input (no typing, no drop menus). Of course, it works even better on my PC (utilizing various hover effects you can't do on a tablet because they don't have mouse over / hover). I've tried the site on an iPad, and the bigger screen and better performance just makes the site that much easier to use. It would work fine on a phone in theory, but I think that would be pushing it a bit in terms of the interface controls being to small to easily deal with and having to scroll around a lot to see everything. Phone designs are a whole different animal from anything with a screen over 6 inches, even.
Interface design means a lot in terms of personal preference, so I can't make any critiques there. I literally haven't been able to figure out how to use some of the alchemy sites I;ve some across, and others have features I like a great deal, enough that I still sometimes visit them to answer questions my DB isn't set up for yet.
-http://keke.itarium.ch/uploads/alchemy/ for comparing values of recipes / effects. One of the best I've found in terms of simplicity of input and quality of output. (Mus simpler than my own, partly because its more focused in purpose).
-There's one out there that takes you actual inventory numbers and turns it into a list of what potions you can make to maximize your profits (like "you can make 3 of this and 5 of this and 2 of this and 7 of this). That's a really freaking hard bit of programming to do, assuming it is actually doing what is says it does. If anybody can find the link, I'd love to bookmark it. Damn wiki mods seem to go on a weekly ramage to "clear out the link spam" from their alchemy tools sections. :rollyes:
Instead of any critique of other tools / designs, I will offer that my site is designed to answer almost any possible question about what Alchemy recipes can do, and is being improved on weekly in terms of both data and features. Its a bit on the techy / math side in terms of working logic for some folks, but that comes with the territory. This past weekend brought book-marking for your settings, meaning you can save your settings and share them with others. For example, here's ahttp://209.46.18.232/wiers.us/skyalc/workbench.php?recipes_tab&show=results Next weekend I intend to do potion values and comments on exceptional effects.