The Blue Letter Bible
This site is a filled with useful resources for Bible study. I use the Bible search tool to quickly find the location of a word or phrase. (Please note that the word or phrase must be entered in the search box in the exact way it appears in the text. If you are unsure of the exact word or phrase, use Google and type Bible at the end of your entry.)
I also check the “Show Strong's” box to display the Strong's Concordance numbers which link to the definitions.
Touch Bible
I have several different Bible apps loaded on my phone, but this is the one I use all the time. I recommend the paid app called the“Touch Bible Loaded.” This particular app is so useful that I don't even carry my print Bible when I'm out and about.
One of the more useful features is the online dictionary. When pressing a highlighted word in the OT, both the Brown-Driver-Briggs Hebrew definition and the Stong's Hebrew definition appear quickly on another page. When pressing a highlighted word in the NT, both the Thayer's Greek Lexicon and the Stong's Greek definition appear instead.