'A learning tool is a tool for your own personal or professional learning or one you use for teaching or training.'
Here is a list of the top 10:
2.) Google Drive / Docs
4.) Google Search
10.) Google + & Hangouts
I was surprised to see how often I already use these tools. Out of 10, I currently use 8 nearly every day. I've never really thought of Facebook, YouTube or Twitter as "learning tools" but I can't argue the fact they provide information on a daily basis. In fact, I'm regularly re-posting or sharing material to colleagues, friends and family.