Search Engines I Recommend to Our Students

I recommend these search engines to our students, grades six through twelve:

Search engines to try:

Apple engine - Teacher selected and approved free resources

Bing vs.Google - You'll see results from both engines side by side. 
Heapr - Search Google, Twitter, Wolfram Alpha and Wikipedia super fast

SearchCredible - Enter a query. Search credible resources. 
Sweet Search - A search engine for students. "Each site has been evaluated by our research experts."

- Computational search engine. Gives you access to the world's facts and data and calculates answers across a range of topics

Chomp - Search for mobile apps through a unique combination of app search and personalized recommendations

pipl People search on the web. Finds high-quality results in pages that cannot be found on regular search engines.

Track This Now - Social media search, topic tracking, news mapping

33 Academic Search Engines - For the serious researcher, from cybrarian77

DuckDuckGo - simple, less cluttered, private
*Google has declared war on content farms.
Got any suggestions to add to this list? I welcome them!