Here are a couple of apps that can meet your requirements -
1. Runtastic Pedometer Step Count It can count the steps irrespective of where you have stored your phone on your body. It syncs all your data to the website so that you can easily access it anytime. You get a training and activity log and also can share your achievements over social media.
2. Steps Mania It can track your walking and running. It also provides a detailed analysis of calories burnt. You can share your achievements on the social media. The app gamifies the walking and running activities wherein you win awards and virtual gifts on completing certain tasks. Such an approach works as a motivation.
3. Accupedo Pedometer It has a widget that can be placed on your homescreen. Widget can be customised as per your needs. It allows you to share your daily log on Facebook.