We’ve all had bad experiences with restaurants, stores or hotels. Maybe you’ve been to a restaurant that served terrible food . Perhaps you’ve been to a store that had high prices and bad service. Or maybe you’ve booked a hotel and found out later that the room was nothing like the advertisement（广告）.       These days, we have a better chance of stopping these unpleasant surprises. We can do this by using apps. An app is a computer program on a smartphone. You can use apps to do almost anything. App can help you play games, get directions, talk to friends, and so on.       If you want to find information about a store or a hotel, you can use a review app. Review apps help us evaluate（评价）service and products before we hand over our money. The idea is very simple. After you go to a restaurant or stay in a hotel, you can post a review with one of your apps. You can say anything you want. If you like a hotel that you stayed in, you can tell people that it was wonderful. If you think that the food in a certain restaurant was bad, then you can tell people not to eat there. Other people can use their app to read your reviews.       Plenty of people prefer not to use these review apps. Many of these people think that it’s a waste of time to look through websites and read reviews. These people prefer to go out and decide for themselves whether or not a service is good . However,  review apps are getting more and more popular every day. Some apps are for exact services. For example, trip adviser gives attention to travel, and good reader pays attention to books. There are also other larger apps that provide information for just about every service that you can think of.