The Emojiyo app is dedicated to helping you find the right emoji for any situation.
Apple's original emoji keyboard is more than a little confusing. Unless you're blessed with a photographic memory, you're often forced to sift through pages and pages of emojis (850 characters organized into six seemingly arbitrary categories, to be exact), to find the one you're looking for. Though the 'Favorites' category lists the last 21 emojis that you have used, it is surely inadequate to accommodate the 250 new characters the Unicode Consortium is set to add to the original keyboard.
Emojiyo allows you to find your emoji of choice faster with a helpful search engine. You will also have the ability to re-arrange the standard keyboard to better suit your organizational preferences.