I think you can try to use Hootsuite with over 35 social networks (Free for the 1st month only) or Buffer (Facebook, Twitter, LinkedIn, appnet, G+) and Free, upgraded if you want.
Besides, you can consider to ask your customers to folow you on social media, it's a good way to increase your traffic rate. You can try to use Better Coupon Box - FREE and NO app logo on your website.
We made this app and now it receives a lot of good reviews, Hope that you'd like it , too.
If you have any problem, just tell me.