Instagram, the mobile photo-sharing service, lets users add artistic filters to their snapshots. (Instagram)

Co-founder Kevin Systrom told TechCrunch the service is nearing another big milestone . At the rate the service is growing, it should have 100 million photos by the end of the week. According to TechCrunch, it took the photo-sharing site Flickr two years to hit that benchmark.

The four-person company is going to concentrate on hiring for now, Systrom said.

The service is eight months old and is currently only available on iOS, and the exec did not offer any details about expanding to an Android app any time soon. Instead, he said he is excited about the new features in iOS 5, such as Photostream and promised new filters are in the works for the app.

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