A electrical engineering calculator for mobile platforms

I wish to have an advanced electrical calculator application designed with mobile devices in mind. (android, iPhone, iPad, etc) This will involve a multi-level menu with links to calculators that will calculate electrical formulas; eg: Ohms law, Power Factor, Voltage Drop, Fault Loop Impedance and other such formulas; Also I would like a storage feature that allows the user to save results in a table or log, also save different "projects" I am happy if the template is built and I build the program and input the formulas in myself. I can't pay more than $150.