Gary from GTR Electronics here. In terms of the Momo9 sold from myself, you can indeed load FaceBook and play Farmville. You can get a FaceBook app via Google Play or get it online via the Web (which is the better version as it's the full one).
Hope this helps, be sure to get in touch if there's anything else I can help with.
I put some steps to help people download apps that aren't appearing on Play on another discussion. Interestingly it was on FaceBook anyway so I've just copied and pasted below. I would note that you can use the same logic and general steps to download any other apk files in the same way.
=========================================== Indeed facebook works on this device. In particular I like the fancy Black Transparent version of FaceBook which looks great with a jazzy live wallpaper in the background. This won't come pre-installed or be available on Google Play, however for those looking to get this version, the following are some steps.
1) Go to settings > security > and make sure the box is ticked against 'Unknown Sources'. This allows you to download and install apps outwith Google Play which is quite handy if you're struggling to find the right one. 2) Open a web browser on the tablet and type in 'facebook apk'. 3) Click on the link that takes you to 'filecrop.com' 4) The very top file should be A00013 black facebook.apk. Click on this and then enter the passcode 5) Scroll down the page and click on the file link that's under the wording "download from hotfile.com" 6) Click regular download and wait 15 seconds, then click the download link 7) The file will automatically download to your tablet, you'll see this in the bottom right hand corner. It will only take a few seconds. 8) Once the download has completed click on the bottom right hand corner (on the little arrow pointing down) and then click on the facebook file. 9) It will come up with an install screen, click 'install' and enjoy!
It should only take about 15 seconds to install, once complete it'll drop a link in your app list. Nice.
Note - you can roughly use the above steps for any app. Simply search the web for the name of the app followed by "apk". Most file hosting websites will follow a similar process to the above. =================================
All the best and have a great Friday! Gary GTR Electronics