I actually bought "Aquarium Handbook Complete" before I returned here to see your offer of a reviewers' coupon. I'm not upset about missing the freebie, I've been waiting for an app like this for awhile & the price seems reasonable assuming more updates are coming. There's lots to love here, making favorites, current tank & pet store lists & are great. With this kind of app, more will always be better but with that in mind it does seem to be missing some important entries. I only keep three species of fish in my two tanks & I was surprised that Angelfish are missing from the database. But I don't criticize for releasing the app with missing entries, I assume they will come with time, there's plenty here to make the app fun & useful.
Unfortunately I need to address the interface design. It seems that you put forth effort to give this app a custom layout that I don't think is working for the content. The short of it is you should hire an experienced graphic designer or stick with the canned iPhone graphic set which is quite nice.
Screen real estate is wasted on iTunesesque reflections. Photos are stretched & distorted everywhere. Fonts are too small making them difficult to read. The window is often split in half which I find offers no benefit. I can't get rid of he keyboard to browse my search results.
An example of an "easy" iPhone interface that succeeds in displaying TONS of information well could be "Now Playing". An example of an advanced layout that I'm happy to pay $25+ would be "iBird" (there's a free lite version too).
In my iTunes review I will be less critical/specific and would be happy to give it four stars for now. I think it's a great Version 1 at a reasonable price. Looking forward to updates & thank you for undertaking this project for us! I wish you success.