 Everyone has their favorite app, that one must-have save-your-life app. Whether it's for the weather, for music, for making sure you have something to read or listen to on the train, you need it. Let's talk about those apps. I grabbed a bunch of my friends around the Verge office and we're going to tell you about our app, that one you can't live without and think everyone else ought to have. The one app I recommend to almost everyone is Hopper, and it's a must-have if you travel a lot like me. It's a free app on iOS and Android for finding the cheapest flights to your favorite vacation spots. Using Hopper, I was able to book a $333 trip to Paris in February and a $575 trip to China in September, while being sure that there were no other flights out there that are better deals. The quality of the flights weren't bad, even though they were certainly on airlines I had never heard of before. It's also difficult to cancel your flights, and there's often a fee involved, so it's definitely something to be aware of. I recommend using the app to monitor flights you have your eye on and keep notifications on so you won't miss your chance to snipe the deals. Friends often ask me how much I flew for, and they're always shocked at the price, so it's a great conversation starter too. The app I recommend for everyone is Google Photos. I needed to free up some space on my iPhone because my photos and videos were taking up too much room, so Google Photos was the answer. The app automatically ported over three years of photos and videos to Google's cloud when I downloaded it, and now I have a ton of space on my phone. It's free for iOS and Android users, and I highly recommend using it for iPhone so that you don't have to pay for extra iCloud storage. You can make albums and edit photos from the app, and it automatically scans your photos and figures out what's in them, and then you can search for a specific thing and pull up all the photos of that thing. I kind of hate that Google knows everything about me, my friends, my family, basically everything I've ever seen or taken a photo of in my entire life, but it's really convenient and it's free, so really it does everything I'd ever need a photo app to do. Just please Google, don't ever charge me. Like probably everyone watching, I use my phone to take a lot of photos, and your default camera app is great if you want to take photos quickly and easily, but using a third-party alternative gives you a lot more control. My favorite of these is called Halliday. It's got a great interface that lets you swipe up and down to quickly change exposure levels and swipe left and right to manually focus, and it also has a number of helpful little UI features that let you frame your shots just so. Now if you want to take your smartphone photography to the next level, then Halliday can also be set to take RAW files which retain a lot more data than their JPEG counterparts that's perfect if you want to get into photo editing. I've been using Halliday for about eight months or so now, and I've taken some shots that I'm pretty happy with. My favorite app is Splitwise, which tracks and splits expenses between roommates and friends. I tend to be the roommate who restocks all the cleaning supplies or household items, so I use Splitwise all the time, and it's super easy to use. First, you create a group with your friends or roommates. Then, whenever someone in the group makes a related purchase like paying the gas bill, they just add the expense to the group and Splitwise automatically divvies it up between everyone in the group. As more people add different expenses, the app will add or subtract the amount each individual owes or is owed. And say you don't want to split the expense with everyone in the group, there's an option for selecting who in the group you want to split the expense with. You can also link it to your Venmo account, so paying someone is super easy, but Splitwise doesn't let you request Venmo payments via the app. Splitwise is free and it's available on both Android and iOS, and I would highly recommend it to everyone, especially if you're the person always putting down your card. Alright, so for me, that one app is Dark Sky, and I feel like a broken record because I've already told everyone in my life like five times that they have to use this thing, but I'm going to say it again because it's so good. Dark Sky is a tiny little weather app that emerged from a Kickstarter campaign, and it does one thing way, way better than any other weather app out there, tell you when it's going to rain. And I mean way better. It tells you the time, down to the minute. It's able to do this by determining the speed and direction of a storm, and then projecting where it's going to move in the minutes ahead. So let's open it up and check it out. Right up top here, first thing, it shows you the current temperature. But what's important is right in the middle, this wobbly blue chart. This is a projection of how much it's going to rain during the next hour. You can see if it's going to drizzle or downpour, and you can see if it's about to ramp up or trail off. That will explain below when it expects the rain to start and stop, telling you down to the minute. But I think it's this graph that's truly a lifesaver. Sometimes you're stuck in a store, maybe it's just started to drizzle and you're wondering, do I book it out of here or do I wait it out? Well, even if it's not going to stop raining, you might see a spot where it's slowing down enough that you can make a dash out to your car. That can also send you a reminder in the morning to bring your umbrella right before you leave for work if it sees that it's likely to rain. It can send you a heads up just before a storm is about to start at any time during the day too. I have it set to warn me anytime there's going to be a moderate amount of rain. If you really want to get nerdy, the app lets you dive in and view storm systems and wind patterns too, so you can kind of feel out how your area is going to be affected. The app is available for both iOS and Android. On iOS, it's a flat $4 fee. On Android, you can try it for free for two weeks, and after that it's $3 a year. I often feel like I've gotten more practical utility out of Dark Sky than out of any other app on my phone. And that might be an exaggeration, but the point is, every time I open this app, it's actually helping me out. And that's pretty awesome. I want to thank Shannon, John, Ashley, and Maria for sharing all these apps with me. If you have a must-have must-share app, let us know down below because we definitely want to hear more. And let us know if you have any tips for the apps that we're already into, since there's always more to find. And if you haven't already, be sure to subscribe to The Verge because we're going to have a ton more tech videos coming up.