Write an Android application

The following details is for a messaging app like whatsapp . I would like to have the same features as whatsapp and also few of the other features that I am looking are : [login to view URL] setting and collaboration with support group, this feature is about where I want to loose weight or achieve some goal. I will create a goal and add my best friends into that goal group. I will be required to update daily at a particular time and my friends in that group can leave their comments. 2. Arranging for a meeting, a feature where I will be setting a a meetup and selecting few places , times : My friends can select their favorite from my list or add a new place or time ,