I have been using e-Sword as my primary Bible study tool for over 5 years and highly recommend it.
There are more advanced study tools available, but e-Sword offers a lot for free. The KJV is included in the initial download, but other Bible versions are also available. Many add-ons are free. Some material is copy-writed material can be purchased as premium content. Between the free and paid resources, you can download almost any Bible version you want.
Some of the Bibles are available with Strong’s Concordance indexing for easy look up. You can view multiple versions in parallel if desired. You can also compare passages in multiple versions of your choice.
You can easily do word and phrase searches in any Bible version you have loaded. You can highlight passages, you can copy verses, you can take notes. Commentaries and Bible dictionary helps are also readily available.
If you want a great electronic Bible study program for FREE, you cannot beat e-Sword!
You can visit the the e-Sword website to learn more and/or download the software at www.e-Sword.net.