This article could be out of date, as it was published 1 year 1 month 12 days ago.

After less than a week on Google Play (formerly the Android market), photo editing and sharing app Instagram has topped 5 million downloads, with an average rating of 4.6 out of 5 from the nearly quarter of a million people who have taken the time to share their thoughts.

The extraordinary uptake has made Instagram the second most-downloaded of Google’s new free apps – behind Rovio’s Angry Birds Space – and seventh out of all free apps combined.

The Android success is a further boost for the company, which was purchased by Facebook yesterday for US$1 billion.

Of course, as many commentators have noted, the popularity of the app has come at a price, with hordes of users on Twitter promising to shut down their accounts now that Instagram is linked to Android and Facebook and thus has lost its veneer of indie cool.

From there it’s only a matter of time before the downward cycle begins, unless the Instagram team – who have been absorbed into the Facebook machine – can work with their new social networking parent to keep the app relevant.

After such a sharp rise Instagram could fade into obscurity just as quickly, leaving a smouldering pile of sepia-toned ash where Facebook once had one billion US dollars.

With an IPO just around the corner, Facebook needs to show potential investors it knows how to handle its money, so there’s a lot more riding on this than just a nifty little app.

Will Instagram go from strength to strength now that it’s a part of Facebook, or will it be the worst tech acquisition since MySpace? Post your comments below.