With Instagram, Facebook chose to allow it to live-on for now – but I suspect it will eventually get fully integrated into Facebook’s brand apps. Unfortunately, Google has not been as kind. They’ve made it clear that they have no intention on adding features to it in the future. It’s dead. And while Facebook only hired the developers and not purchased the apps themselves, they’re essentially dead as well.

I’m not suggesting that you should not buy apps from independent developers. They’re what makes the Apple community great. And I absolutely do not blame any developer for selling their company for large sums of money. They worked hard to create a great app or service and they deserve the rewards.

But you should take these recent acquisitions into consideration when you purchase your next app that may be a mission-critical one. Let me give you an example.

I love Default Folder X. I consider it to be my most important utility, and the first thing I install on a new Mac. I have no problem shelling out any upgrade fee the developer chooses to charge, because I know it isn’t going anywhere. Default Folder has been around since the pre-Mac OS X days. To my knowledge, they’ve never had to resort to drastic price drops or bundle promotions to sell the app, and the developer already has it ready for OS X Mountain Lion. And I can’t see any company outside of Apple wanting to buy the app because it’s such a niche app – for power-users only.

At the other end of the spectrum, you have an app like Toast Titanium that is on its third owner (currently, Corel owns it). While Toast has been around a long time, I wouldn’t recommend buying it anymore because there are plenty of other apps to burn optical media discs, including Apple’s built-in burner, and it appears that nobody has found it to be profitable or it wouldn’t have been sold yet again.

The cost of applications available on the Mac App Store are very affordable. It’s hard not to take a chance on a $3.00 application. But if you’re going to rely heavily on an application, you should probably think hard about the longevity of the app and the developer. Is the developer charging enough to make a living off the sale of the app? Is the app a “trendy” one that you think may go away or change dramatically in a short amount of time? Are there larger, more established companies selling an app that does the same thing? In the case of Sparrow – I almost saw this coming, which is why I never purchased the app.

One last thing to consider. Is the app based almost entirely on another service? I love Tweetbot – and can’t wait for the Mac version to ship. But something tells me it won’t be long before it dies, because it’s entire existence is based on Twitter allowing it exist in the first place. If Twitter decides they no longer want to allow 3rd party apps to use their APIs, Tweetbot and all the other 3rd party Twitter apps are dead.