Recommended and mentioned products
Freedom is a productivity hack that lets you block apps, websites or the entire Internet on iPhones, iPads, Windows and Mac computers.
Freedom. For $2.50 a month, Freedom will block all social media sites on all your devices during hours you specify.
More suitable with Google Chrome, this service enables you ensure you do not waste precious time on updating Facebook status or chatting with people.
StayFocusd is a chrome extension with over 500.000 users, that lets you set time limits per site.