First, you'll be able to access FarmVille Express in one of two ways. Either go into your Facebook app on your iPhone / iPad (Android support coming later) and tap on a FarmVille request to be taken to FarmVille Express automatically, or navigate to m.farmville.com on your smartphone or tablet's web browser.
As a side note, if you don't wish to play the game right now (or simply don't have any crops that require tending), you can also use the app to respond to friends' wall posts, receiving the bonuses accordingly, as seen below. Also, you can't officially use FarmVille Express on a traditional computer, as it will redirect you to the Facebook app proper.
Once you've made it into FarmVille Express, you'll see two major areas: "Your Messages" and "Your Crops." This is the case regardless of how many farms you currently use. The Your Messages section shows up on top, and allows you to respond to any free gifts that have been sent to you or individual requests from friends for building materials, quest items and the like. You can send free gifts from this area to all of your friends or specific groups of friends (based on who you choose), and you can even add neighbors directly from this section.
As for the "Your Crops" section, you'll only see one farm's crops at a time. For instance, since the last farm I visited in the game on Facebook was Lighthouse Cove, these crops appear for me by default. As you can see below, however, my Chandler Blueberries aren't yet ready to harvest. To get to other farms, I would simply tap on the Options menu below and tap "Select" on the farm I would like to make active. Pushing the Back button returns you to the previous screen, where you can then begin to harvest and plant any crops that are ready.
Unfortunately, there's no way of telling how many hours or minutes crops have left before they're ready to harvest as of this writing. Additionally, there's no way of using fuel to harvest all crops simultaneously (although that's coming soon), so you'll need to tap on the "Harvest and Replant" button (or just "Plant" if your fields are currently empty) as many times as you have crops that are ready / empty plots. It's time consuming, tapping the same button hundreds of times in some cases, but it's actually the best mobile version of FarmVille I've ever seen.
As a final note, you can't access your Gift Box in FarmVille Express, so tree farming, using Bushels or even using a Fertilize All on your newly planted crops is out of the question. Still, if you're going on vacation, or simply can't make it to a regular computer before your crops will wither, this quick and simple process is literally a farm saver. We'll make sure to let you know when Fuel farming comes to FarmVille Express, or when other features are added in the future, so keep checking back.
Have you tried out FarmVille Express on your phone or tablet? Do you wish you had access to other features, or do you appreciate such a streamlined version of the game? Sound off in the comments.