Litwe is a lite mobile web based Facebook and Twitter client application. It's built using vanilla PHP. It used TwitterOAuth to connect with Twitter's API and Facebook API to connect with Facebook. Although initially I just built it primarily for my own personal purpose, I eventually published it on domain litwe.info. And it turned out that there are many other people like me who liked to use it. This web app still run until no one else were using it anymore.
I was a bit late in adopting smartphone. I still used feature phone while many other people have had their Android/iOS gadget. So, I didn't have the luxury to use tweetdeck, ubersocial or any other fancy social media aggregation apps which were only available on smartphone. So.... I built one for myself. An app specifically designed and developed for my own use on my feature phone. I wanted an extra lite mobile app which won't hog my data usage but still have a fully complete facebook & twitter features (mention, retweet, comment, DM, etc)
This was my first time dealing with REST API. I didn't have any prior knowledge about it before. So, I had to really understand the concept of it before I stumble down the Facebook & Twitter API code. It took a while for me to grasp enough understanding of the concept of communication between web applications.