Free Phone App designed for Ind Electrician, Engineer or Manufacturing?

Do you know of any Free Smart Phone Applications (Android, IPhone or Blackberry)designed specifically for Industrial Electricians, Industrial Engineers or specifically for use by Manufacturing persons?

If so please reply with link, name etc. If you know of more than one, please list in order of what you think is the best ones. If you know of a site that has several free phone apps specifically for industrial use, let me know that too.

I am trying to decide if there are enough free Smart Phone Apps for our industry out there to warrant adding a new section for that to our free industrial download site at www.industrial-ebooks.com

Thank you all for your help.

Don