What In The World?

During a puzzle, click on the shopping cart in the top right. There will be a connect to Facebook option listed. Click on it and connect it to a Facebook account. Follow the prompts and when it resumes the puzzle, the achievement will unlock.

A Lazy Susan posted a great addition to this solution. To start off, you need to have the facebook app installed for this to work, at least I did. You also need to have the facebook account setup with your Microsoft account email address. Again, I did anyway. It may work otherwise, but I tried with three different facebook accounts and it only worked when I created one with my microsoft account email address.

You don't actually need a Facebook account to get this achievement. Below is a step by step guide as to how I unlocked it.

Boot up the game.
Click on the Facebook icon at the bottom right of your screen.
Let the Facebook page load up.
Click the back button on your phone to take you back to the main menu of the game.
Give it a few seconds and it should pop.
If it doesn't, hold down the back button and force close the game.
Launch the game again and it will pop. (I had to do this for a couple achievements for this game)

Hope this helps anyone who needs to knock this out.

So after countless tries, finally got the achievement to unlock today, on my first try with these precautions. This is how I did it(with the help of others):

-Create a Facebook account with the same email as your Microsoft account if you haven't already.

1.Log in to the desktop or mobile site of Facebook(not the app). Go to account settings, then to general settings, email adress and deselect "use your facebook email"

2. Go back to the account settings and then go to apps. Here delete "Make in the world".

3. Have Facebook app installed.

4. Have the latest "What in the World?" update installed.

5. Start What in the World?, select a puzzle you haven't completed. Select the shopping cart in the top right hand corner. Select connect to Facebook.

6. Fill in your email and password if you're not logged in yet, and give the app the 3 functions it asks for. Your phone returns to What in the World? and the achievement unlocks.

To put this straight and very simple to understand:

1. Download and install the official Facebook app from the Store if you haven't already.

2. Log in or sign up with THE SAME ACCOUNT you used to download the game from the store (and for the the app games which redirects to xbox.com) which is the one identified in Settings->email+accounts as "Microsoft account" with the windows symbol; all other microsoft live accounts you have which are not currently your main account are identified as "outlook accounts"; none of them worked for me at least (see notes), only the one mentioned above.

3. As soon as your Facebook app is connected to your Windows Phone account open the game and simply click in the shop icon-> connect to Facebook; it will redirect you to the app; as soon as your account loads completely you don't need to like the page nor do anything; if it asks you "allow to connect" say "yes" but when/if it asks you to "allow to post for you" you can say yes or no, it does NOT make any difference, I remember I said "no", obviously.

4. Exit the app without logging out of Facebook yet and return to the game, the achievement will pop in a few seconds. Once the achievement is unlocked you are free to delete your account and uninstall Facebook app or log out of Facebook app from that account and log in with the one you use normally.

Notes
To clarify some doubts:
1. You can't do it from the browser or any unofficial Facebook app.
2. Some people (thanks to GJChester) managed to unlock with other accounts than the "Microsoft account" in your WP, but I lack details about it (feel free to contribute if you did this) therefore this solution is the only one I can guarantee to work with 100% success.
3. You don't need to be playing any puzzle but you don't need to be in the start menu either, the only thing that matters is that you see and click the shopping cart little button at the top right corner of the screen at any time in the game.


I hope this helps and finally clarify all doubts about this awful glitch!!


PS: This is my first solution. So please be nice :) I tried everything and arrived to the conclusion that this is the only way I found of doing it without cheats, third-party software or jail-breaking your phone. If you found another way that involves any of these methods please keep it to yourself, any other accounts which worked for you please tell me so I can add here please! if you think something is wrong or inaccurate with my solution I'd really appreciate you pointed it out nicely before immediately voting it down ;) thanks

I don't know if I got lucky or what, but I loaded the game up, pressed the Facebook "F" icon on the lower right, and I popped the achievement as my phone was switching to the browser. I didn't have to log in or anything.