Consult the Reviews
If you want a specific kind of app, but you’re not sure which one to choose, check the Web (including articles on PCWorld.com) to see what’s reputable and popular. After identifying a couple of promising apps, check the customer reviews for each to confirm that they work for other customers. The Android and iOS markets use five-star ratings; an app rated at below three stars probably isn’t worth your time.
Read a few recent reviews to see how the app’s latest update is performing. Even if an app has earned stellar ratings over several months or years, the most recent version may not work well or may introduce new features that users don’t like.
Check how many downloads the app has. Unless you want to test an app, don’t be one of the first 1000 people to download it. Because the iTunes store doesn’t list a figure for downloads, you’ll have to estimate the probable number based on how many reviews it has received.
If you decide on an app that looks reliable but costs money in the Android Market, visit Amazon.com or other third-party app stores like GetJar or SlideMe to see if they offer the same app for free. Of course, check the reviews for the app on those websites as well (to confirm that you’re not downloading an impostor malware app), and make sure that the app you’re downloading isn’t asking for too many permissions. For example, if you’re downloading a dictionary app, it probably doesn’t need to ping your phone’s GPS component for any reason.In buying apps, as in buying anything else, a little common sense goes a long way.