You can enter the Kanji Explorer either from the main reader screen (via the Tools/Kanji Explorer menu option), or by pressing the Explore button from any Kanji Details screen.
The first time you enter the Kanji Explorer, you will be asked if you want to create a Kanji Map database. Press OK to create the database, which takes approximately 2 minutes.
You will then be presented with the Kanji Explorer screen, which shows the kanji you chose to explore in the center, surrounded by up to six other "related" kanji characters.
Tapping any of characters surrounding the central character will show you a two-character Kanji compound incorporating the central character and the selected character. Tapping the same character again will make it the new central character; in this way you can follow a chain of kanji characters around and hopefully gain a better understanding of their meanings. Note that some characters will have fewer than 6 characters surrounding them, and occasionally you may find a character with none.
Tapping the central kanji character will show you one of its readings and the meaning of the character taken alone. Tapping it a second time will take you to the Kanji Details screen for that character.
The buttons at the bottom of the screen have the following effects: