It's not necessary to have an app manager/task killer. The platform manages memory just fine, better than any other phone including iPhone. Each app is installed as it's own user and runs in it's own sandbox (JVM) so if it crashes, it does nothing to the rest of the phone including any other apps running. The underlying OS is linux..the same OS that is used on a lot of desktops and servers world wide. It manages memory very well. What you are going to run in to is applications that don't have a clear cut way of exiting. This is partly bad programming, but also partly a mind set that android devices can run multiple apps and switch between them at will. If an app you run has an exit option, use it, it will close. If not, and you just use the back or home buttons to leave it, it may run, or the OS may suspend it while you're not using it. Really depends on the programmer and what "hooks" they listened for to take care of the app in different situations. Coming from an iPhone is going to be the biggest problem for Android uses. That one little button always closes the one running app, and puts you back in the home screen. On Android, that isn't so. If you don't use the exit option (if provided), you may very well NOT be exiting the app. Application developers can put in hook to listen for when a user goes back, or hits home..and could very well exit the application to "mimic" iPhone like functionality. But most I've seen don't do that.
As for what you can do with it.. the question should be phrased..what can't you do with it. Android is a very very open platform, far exceeding the iPhone and any other phone out there. The fact that Google is building an operating system that will include Android, tablet devices and other devices (dvd player for one, DVR another) that will have Android in it, and so on should tell you that Android is much more than just a phone platform. With Java the language of choice for Android apps, you've got the largest developer base in the world with the largest (or perhaps 2nd largest..not sure if it passed up C yet in this respect) libraries at its disposal. As well, android based devices (mostly phones) are going to be part of every phone carrier, including in early 2010 the largest carrier in the world in China, that hosts more than 500 million subscribers. If you don't think java developers aren't going to jump on this bandwagon... oh they will! There are 10s of thousands, if not 100's of thousands of java developers world wide, and when Android hits most devices and all these carriers, it will grow a lot faster than iPhone. Sure, iPhone has 100,000 apps and 45 million users. Wait till the 88 million Verizon, 500 million china, and some other millions of other carriers deliver android devices, all coming in the next few months.
So the question should be.. what WONT it do.
