I check out multiple apps every week. The vast majority of them I use once and mercilessly delete. (I'm looking at you, Acorns.)\n[Related: The Best iOS and Android Apps of 2013]\nThe apps in this post? Keepers, every one. I reviewed each of the following seven apps during 2014. Some I've used for several years, but they received significant updates this year. Others were welcome surprises. They're listed below, in alphabetical order.\nAcompli\nEmail is a problem that seemingly every app developer is trying to tackle. Acompli gets it right by keeping it simple. There's no "reinvention" of email that makes you relearn how to check your friggin' messages. (Google Inbox, did your ears just burn?) Acompli just sorts your messages into two tabs: "Focused" (which is where your important messages go) and "Other" (where your Access Hollywood email alerts go). The app works beautifully with your calendar and makes attaching files super simple. Microsoft recently acquired Acompli \u2014 yet another smart move the company made this year.\nCarousel\nThere's nothing particularly awesome about Carousel. However, I use it multiple times a week because it makes syncing smartphone and tablet images and videos to Dropbox a nearly brainless activity. It also makes it easy to find your content and watch videos you uploaded. Therein lies the beauty of a well-crafted app: It does a few things well, and it's simple to use. (Here's my original review.)\nGoogle Play Books\nNonfiction ebooks, particularly reference books such as travel guides, have long been hampered by poor search capabilities. Google found a solution to this problem in a Google Play Books app update for Android not by improving search (surprise!) but by adding a new "skim" feature. You can easily flip through thumbnails of pages, just as you'd flip through dead-tree pages of a printed book. Your move, Amazon.\nKindle\nAmazon isn't to be trifled with, particularly in the ebook reading experience. This year I became hooked on the Kindle "Whispersync for Voice"\u00a0and, to a lesser extent, "Immersion Reading" features.\nThe first feature lets you synchronize certain Audible audiobooks with their Kindle ebook versions. When I'm out for a hike, I can listen to an audiobook. When I'm hunkering down for the night, I can pick up the same book in ebook form, right where I left off. Yes, you have to buy the book in both formats. If it\u2019s a long book, there's a terrific narrator, or you like to underline stuff you read, the investment is worth it, in my book. (Yes, pun intended).\nImmersion Reading combines the two, so you can hear audio narration as you read the ebook. It's nice, but I don't use it very often. It's also only available on some Amazon Kindle tablets and the Android Kindle app.\nMicrosoft Office Mobile Apps\nIn 2014, Microsoft finally read the memo: Mobile is kind of a big deal. The company's ostrich act was getting it nowhere.\nThe Redmond wizards recently made it possible to create and edit Office files on iPhones, iPads and Android phones\u00a0without climbing the Office 365 paywall. You can't access all of the features in the mobile Office apps for iOS and Android for free, but you can still do a lot without sticking a stubby toe in the Windows pond. I can't wait to see what Microsoft does in mobile in 2015.\n\nYahoo! News Digest\nYahoo, like Microsoft, reinvented itself in mobile during the past year (and for both companies, not a moment too soon). Exhibit A is this excellent\u00a0news app, which serves up the top 10 stories twice daily. Each story is easy to read, and collectively they represent a fairly broad selection of topics, including politics, technology, world news and entertainment. Along with Circa News, I can quickly get updated while standing in a supermarket line with\u00a0Yahoo! News Digest. It sure beats the National Enquirer headlines.\nThe Weather Channel\nI have six weather apps on my iPhone, but the one I check first is the Weather Channel iPhone app. It tells me everything but the humidity level in my bathroom after a hot shower. Along with hourly and 10-day forecasts, the app offers weather videos, a radar map, skiing conditions (if applicable), a flu report, pollen index, current airport conditions, and boat and beach conditions (again, if applicable). Forecast: You're going to want the Weather Channel app,\u00a0despite its in-your-face ads.