Today, there are a lot of aplications all over the world. With this many kind of aplications, they have different uses. A startup build to make many works easier than before. You may see an example of startup applications such as facebook. According to my assumptions, facebook is a startup because this applications can make everyone knowing their friend from the past time goes (elementary school, colleges etc). With this applications, everyone can make new friends from anywhere. The other example is twitter. I think everyone know about twitter. They can make any simple sentences or status and share to others. Read this too : 3 Essentials plugins for your wordpress blog
So, do you want to make a startup? Making a startup is not easy as you thought. It needs a brilliant idea so that useful to others. But sometimes, the ideas come from a simple matter. Just thinking and then try to achieve the goal for the startup applications. Do hope that we can make such an applications soon. Praying and trying.