I run a few websites for organisations and discovered that Instagram can be a powerful tool for sharing images and short captions to Facebook and Twitter. It is possible to use your mobile and be able to send a message out to your other social media outlets using this method as you can see by this screenshot:-
These accounts have to be connected up to Instagram which is a simple matter to do on your mobile. Create your message and then choose where you would like to send it. This screenshot from my desktop shows your options.