In the first screenshot, you should align the numbers to the right and put in some decimal separators, otherwise it's like guessing the number of zeroes in the AH ;-)
Otherwise, great job. Gonna try it out right now!
Okay, just installed, here are some comments (used my phone, tablet is at work):
-You should put a description for the normal gem in as well, the empty selection in the dropdown menu is... awkward.
-On the start screen, it asks me to provide a price for a gem. Didn't know how to proceed. Then I found the small little question mark on top right (that is unusual for Android apps) and read the "how to use" guide. It told me to select "done" in the action bar; problem is, I think I don't have an action bar in Android 2.3.3. So I kind of can't use the program the way you designed it.
-If I select topaz and click on "possible profit" it says "Today's gem is %s!" and is "calculating profits" but never shows anything. Broken? Under construction? ;-)
-There should be a small label on top of the dropdown boxes. Like "Gem color:", "Gem quality available:", "Gem to be crafted:"
-The start page should not be the "define AH cost" page, but the "upgrade gem" page. Then, upon selecting the gem color and quality, you could add a popup asking for the current gem cost on the AH for the "originating gem" that you want to use for crafting the upgrades.
-Like mentioned above, the numbers on the detail page need decimal separators and should be right-aligned.
Sorry for all the blunt, unadorned feedback. It's better than I made it sound. I actually like the overall visual design of this app and the idea, but at least on my phone with Android 2.3.3 it lacks a bit usability. But I'll stick to it and look forward to your updates! :-)