How old are the apps on your smartphone? Is it time for an update? Here are three apps for you. Try them out and have fun.

Duolingo

    Learning a foreign language doesn't always mean you have to sit in a class and take endless exams. An app called Duolingo has been designed to help you memorize (记住) new words and grammar in creative ways，such as online lessons，games and interesting exercises. For example，one exercise asks you to put words in the right order to make the correct sentence. You can also try translation practice.

Douban FM

    A music app is a necessity for almost every smartphone now. Douban FM might be the right thing for you.

    There is no playlist on Douban FM--songs just keep streaming (播放) one by one. You can use the “heart”, “trash” and “skip” buttons (按钮) to mark the songs you like，don't like and want to cut short, respectively (分别地). Those marked with a heart will be stored in another list as your favorites for you to listen to anytime you want. Douban FM also has different channels (频道). There are many types of music, such as blues, jazz, and pop. You can choose the music for outdoor activities, work or studying depending on your mood (心情).

Flipboard

    It is one of the hottest news apps right now. With Flipboard, you can make everything personal to you. All you have to do is open up the app, “flip through” to select whatever interests you，and click the “+” button. At the end you'll have your own magazine, complete with a front page, new articles, and information.

    As the G20 Leaders Summit(峰会)kicked off on Sept 4, Hangzhou, the host city, took measures to promote its reputation for entrepreneurship(企业), as well as its many beauty sports, to those overseas people.

    Although many may have been surprised when Hangzhou was chosen to host the summit over bigger cities such as Beijing or Shanghai, economic statistics suggest that it's well deserving of the honor.

    When the national economy grew at 6.7 percent in the first half of this year, the lowest in more than two decades, Hangzhou steamed ahead with a huge 10.8 percent growth, becoming one of the only two cities in China, alongside Chongqing, with a double-digit growth rate.

Walking along the streets of Hangzhou, through centuries-old paths and along the Broadway—like Yan'an Avenue, a tourist can pick up whatever he or she wants with just a smartphone, via Alipay or WeChat Pay—no cash or credit cards needed.

    And starting this month, one can also rent public bikes simply by scanning the QR code(二维码)with a smartphone.

Meanwhile, a short video showing the beauty of Zhejiang Province and its capital, Hangzhou, was being aired on CNBC channels during prime time until Sept 12.

    The promotional video, created by CNBC's Catalyst Content Studio, highlighted some of Hangzhou's most charming attractions.

From eye-pleasing beauty spots like the Qiantang River and West Lake to the towering headquarters of leading Internet corporations, the promo(宣传片)showed how the city built its culture on a long history of commerce and developed into a vast modern center of technology, imports and exports.

    Shree Bose is one of the most impressive kids graduating from Fort Worth Country Day High School this year. Bose has a large circle of friends, and there's one who you may have heard of: President Obama. He has twice publicly recognized her achievements in cancer research and spoken with her in the Oval Office.

    If that isn't enough, Bose recently gave a TED Talk about her work with the cancer drug Cisplatin, which also won her first prize at the Google Science Fair and recognition as one of Glamour magazine's Young Amazing Women of the Year.

    After watching her grandfather struggle with liver cancer, Bose was determined to help out in any way she could. As a high school student though, her scientific choices were limited. She reached out to various hospitals and research centers, but doctors turned down her requests because they felt she was too inexperienced medically.

    Only the North Texas Science Health Center respected her determination and chose to guide her. The results were amazing.

    Bose chose to study a protein (蛋白质) and its reaction with the cancer drug Cisplatin. She noticed that when she prevented this protein from growing, Cisplatin was allowed to begin destroying cancer cells once again.

    “My project not only contributes to the understanding of the relationship between the protein and Cisplatin, but also suggests a newer, more effective treatment for patients who resist Cisplatin,” Bose said.

    Bose's achievements aren't limited to the lab, though. She was also captain of her swim team and editor-in-chief of her school paper.

    Bose is currently getting practical experience at the National Institute of Health and she'll be attending Harvard in the fall. She plans to study molecular biology and go to medical school. Eventually, she would like to be a doctor.

    Around the world, 62 million girls are not in school. The White House's Let Girls Learn effort aims to change that.

    At 13, Hawa Abdulai Yorke left her family's home, in Ghana, Africa, to live with an aunt who promised to send her to school. Instead, the aunt put Yorke to work as her maid. Determined to go to school, Yorke returned home and began selling water in a nearby city to raise
money for her education. She did that for three years. What hurt most was that her father had the money to pay the school fees. But he chose to spend the money on a motorcycle.

    Yorke's story is familiar to girls growing up in Ghana. There, a girl's place is in the home. Educating girls is considered a waste of money.

    “It happens more than it should, where parents have money to send their girls to school but choose not to,” says Ryan Roach, a Peace Corps volunteer in Ghana, where nearly 55% of girls are not enrolled in secondary school. “Cultural beliefs say education is not a wise investment(投资)”

    The White House's Let Girls Learn is working to change this view of girls' education, in Ghana and in countries worldwide. First Lady Michelle Obama says parents have to be persuaded that girls' education is a better investment than marriage or household labor. A World Bank study backs that up. It shows that for every year of secondary-school education, a girl's earning power increases by 18%.

    Today, Let Girls Learn works in 13 countries, and there are plans to expand the program. Recently, Let Girls Learn hosted a 24-hour event at which girls in different parts of Ghana joined Peace Corps volunteers, tech experts, and university students to brainstorm creative solutions for the barriers to girls' education. Yorke's team came up with an idea for an app that sends a recorded message to parents' phones from a Ghanian celebrity about the benefits of girls 
attending school.

    Yorke, now 22, is about to finish high school. Thanks to Let Girls Learn, she plans to attend college and study computer science. She says working alongside women college students at the Let Girls Learn event strengthened her determination. “I'm focused on my books,” says Yorke. "I know if I study hard, I, too, can go to the university and live a happy life."

    There are excellent reasons for anyone to seek out the optimistic. Optimists experience better health outcomes, live longer and are more satisfied with their relationships. Optimism enables people to hold on in the face of difficulty, while pessimism leaves them depressed and even expecting failure.

    I want that hopeful, optimistic outlook for my children. But many times we may feel pessimistic. The result of negativity makes me worry that my kids' future will be uncertain. Fortunately, research suggests ways to help our children grow up with an optimistic attitude and maintain a happier outlook ourselves.

    Humanity has improved by many measures, but that success has become the water in which we swim, and like fish, we take the water for granted. While we fail to notice the positive, our brains naturally emphasize on the negative. With practice, we can help our brains to give the good stuff equal weight. Dr. Hanson's advice: when you hear a great story or achieve something in your own life, deliberately rest your mind on that experience and stay with it. Sink into that feeling as it sinks into you. Describe what you're doing to your kids, and encourage them to dwell on their joys and pleasures as well.

    Following the "big scary" news can leave us feeling helpless. Find something in your area that makes you feel hopeful, and make it a part of your family life. Researchers found that when people with a pessimistic outlook use positive language to describe situations they find upsetting, their feelings about the situation become more positive. That's something we can try at home.

    Raising optimistic kids is hard because it demands that parents abandon the pessimistic perspective that's the easiest response to pessimistic times. Put your energy into making sure you and your family are a part of the world around you. That might mean simply joining and being part of local clubs that feed our natural human need for connection (not of the digital kind).

    Here are some great people and their achievements.

    Mary Anderson ­ windscreen wiper.

    Back on a freezing winter's day in 1902, Mary Anderson was travelling by train through New York City. Snow was falling, forcing the driver to stop repeatedly and get out to clear it. Each time the door opened, Mary suffered a gust of sub-zero air. She had an idea: why not make some kind of a rubber blade that could be operated from inside the vehicle? And that's exactly what she did.

    Josephine Cochrane ­ dishwasher

    The dishwasher dates back even earlier to the 19th century, and to the dinner parties thrown by a lady called Josephine Cochrane. As a frequent host, she wanted a machine that could wash dishes faster than people. Her response was to develop what was to become the first commercially successful dishwasher. Interestingly, innovation was in her blood: her grandfather had invented the steamboat.

    Stephanie Kwolek ­ Kevlar

    Kevlar is the lightweight fibre used in bulletproof vests. The material is used by millions every day and has saved countless lives. The super tough fabric is also used in objects ranging from gloves to airplanes. Incredibly, its strength-to-weight ratio(比强度) is five times higher than steel. Again, it was invented by a woman, the American chemist Stephanie Kwolek, in 1964.

    Grace Hopper ­ first compiler(编译程序)

    One of the most important inventions of the 20th century must surely be the computer programme. The world of programming is unbalanced in terms of gender. Men vastly outnumber women, and take home around 30% more pay than their female counterparts on average. But back in the 1940s and 1950s, women were at the forefront of this new field. Grace Hopper is credited with inventing the first compiler in 1952, which serves as the bridge between code and the binary(二进制的) ones and zeros understood by computers.