You download an app on your tablet or phone, and it's working nicely - only there's a little feature you'd like to have added, or there's just some funny quirk that you'd like to have fixed or functionality improved. You use some public or company provided service and feel the need to give feedback in one way or the other. Something needs to be corrected, and you think to yourself: to be active or just adapt and dismiss - after all, searching for the feedback forma or email addresses etc. is just a pain in the behind.
Search no more! Whereas quite many instances provide easy access to their contact forms or development blogs that can be commented in this purpose, there is an even easier, and quite probably more effective way of making a difference: social media, namely Twitter.
Most companies and even public service providers follow Twitter hashtags about the company, it's products and related companies and products, their competitors. They will find your feedback in Twitter and the feedback being given publicly instead of in a feedback form that just gets buried somewhere, it is more likely to induce action on their part. They face the chance of a followback, when the whole Twitter community and their competitors have seen the tweet. They need to respond in one way or the other.
The other thing of course is these Facbook movements. Somebody sees something that needs to be corrected and creates a Facebook page, advertises it, gets followers and in the best case scenarios, makes real difference. A good example of this was the fight for this Camionnette coffee shop van in Facebook. Our beloved city here had forbidde this van to operatw for no obvious good reason, other than sheer byrocracy. So, the people around here decided put some pressure on the officials with this Facebook page movement and finally the city bent under it and gave the permit to this van.
Facebook works well for this kind of bigger issues, but for smaller things, Twitter is quite great, as stated earlier. I myself have used it for this kind of interaction with service providers a few times now, and have really been quite positively surprised by the quick responses, both in Twitter and as e.g. app updates.