Logos Bible Software is described as 'Digital library application for Bible study. In addition to eBook functionality, it includes extensive resource linking, note-taking, and linguistic analysis for study of the Bible both in translation and original languages' and is a Bible Study tool in the news & books category. There are more than 50 alternatives to Logos Bible Software for a variety of platforms, including Android, iPhone, Web-based, iPad and Windows apps. The best Logos Bible Software alternative is e-Sword. It's not free, so if you're looking for a free alternative, you could try YouVersion or AndBible: Bible Study. Other great apps like Logos Bible Software are Bible by Olive Tree, JW Library, BibleGateway and The Light.
At least with respect to their Windows version, Logos is very confusing to use. Not very intuitive. Logos is becoming the king of the hill in Bible software because it is buying up the competition and because other commercial desktop apps for Windows are going out of business. inWord is a new kid on the block and is little known, although I think it is more useful than Logos.