From Infotopia:
"Infotopia is an academic search engine accessing only trusted websites previously selected by librarians, teachers, and library and educational consortia. Infotopia is recommended for students, teachers, and especially, homeschoolers. Infotopia was created by, and is maintained by, Dr. Michael Bell, former chair, Texas Assocition of School Librarians, and Carole Bell, former middle school librarian and director of libraries."
"A Complete Guide to Using Google Earth in the Geoscience Classroom."
Contains plenty of resources and helpful tips for teachers in other subject areas.
From Mathination:
"Mathination introduces a revolutionary new way of solving math problems on the iPad by simply touching them. Rearrange terms by dragging; simplify expressions by squeezing; and multiply them out by stretching. Enter any algebra problem from any textbook and solve it with Mathination. Just type in the problem using Mathination's specialized math keyboard."
From Apple App Store:
"Mathination also includes a library of sample problems covering basic algebra, polynomials, factoring, and rational expressions."