The site right now offers books by authors including E.M. Bounds, G.K. Chesterton, Andrew Murray, A.W. Tozer and Charles Spurgeon—and promising many more—each of which can be read free online or downloaded—formatted for Kindle [MOBI], ePub, or PDF—for $.99. Luke, who is an SBC pastor, also offers a membership with unlimited downloads "forever." It's a site I've bookmarked and will definitely re-visit.
Deep Roots Library — Old Theology. New Technology. Deep Roots Library.