In Mantis 4.0, there's an "Analyze Verse" screen that works like this:
I'm reading, say, the ESV Bible, and tap on a verse number, say for Genesis 1:1.
I choose "Analyze Verse".
Now, in the Analyze Verse section, "Compare" is highlighted and I see the ESV version of Genesis 1:1 at the top. At the bottom I can individually open and close any combination of other versions that are installed. (So I could view, say, ESV, NASB, MSG, and NKJV all on one screen.) The selections you make are "sticky" so these items remain open/closed for the next verse you analyze.
Next, I tap on "Commentary" and I can open and close any installed commentary for Genesis 1:1. If a commentary happens to reference another Bible verse, I can tap that reference to open it (in line, right inside the commentary) and it will display the ESV version of that verse (because the ESV is my currently selected Bible.) Tapping the reference again closes that verse so I can continue reading the commentary. While the verse is open, there's a link to jump to that verse in the ESV Bible, if I want to jump over there and read in context.
Next, I tap on "Define". Here, again we have the ESV version of Genesis 1:1 at the top, and the list of installed dictionaries at the bottom. Tapping on a word in the verse (say "heavens") will automatically look up that word in all the installed dictionaries, and again, I can open/close dictionaries individually.
Finally, there's a tap for "My Notes" where I can go to view and/or edit my personal notes on this verse.
At the top of the Analyze Verse screen are buttons that go forward and back one verse (to analyze the next verse, say) and a back button that returns to the ESV Bible where I was reading.