18- How can I check that the question and answer are correct ?

First you click settings from the footer menu. Go to Display tab. 
Then you have to make "Show tags in" to open in "WikiMaster" (former named WOKwiki)

Now you can enjoy to learn more in My Flips: After you flip a question and have answered, the tags attached to the question will turn up blue in My Flips (or in Home).
Below the alternatives Tags will appear . Clic on the Blue Tag will open the Wikipedia article in the WikiMaster app. WikiMaster is a free app in the WOK ecosystem. You learn more and can take a quiz or challenge about this Wikipedia article or just read to learn more. In WikiMaster there is about 330000 questions that do not yet have images to be able to flip in WikiFlip. So this function is a great way to learn more about things in the World of Knowledge.