UnDistracted App - Use social media in a useful way. Control Facebook, YouTube, Twitter, Reddit, Netflix and LinkedIn in a responsible way.
Youtube Detox - Distraction-free Youtube search
CUBI - See your life in weeks
You No Cards - Hide YouTube end cards and channel logo with a single click
Newsfeed Burner - Burn away distractions on Facebook, Linkedin and Youtube
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.