Google is the most used search Engine in the world. It has a simple yet very useful design. All Android and iOS phones come pre-installed with this app.
We can search about anything on the web and within half a second Google produces the results and shows it on our phones. Apart from searching we can check out our emails, bills, flights, currency rates; use calculator and play simple games(like attari breakout).
I get amazed when I think about the huge size of the databases and the fast speed of giving out the results. It has the biggest databases in the world in which are saved copies of the web. And yet it gives the results within half a second of the search enquiry. However slow Internet speeds may increase the time taken by the search results to reach our phones. I think it is one of the most useful apps on our phones.