Phthong helps you to learn the phonemic symbols. But Brits beware, it's for Canadian or American English and doesn't use the same set of symbols (most British EFL teachers use the symbols that are in Adrian Underhill's Sound Foundations chart ).
Jan Mulder's phonemic script writer use this with MS Word. This is a great tool but there doesn't seem to be any documentation. Installing this nifty tool automatically installs a font called phonmap into your Word program. Write your script in the tool, click on Paste, and then change the font of the pasted text to phonmap.