Co-founder Kevin Systrom penned a long blog post to commemorate the news, chronicling Instagram's modest beginnings in a chilly co-working space atop the San Francisco Bay and the journey to becoming a global phenomenon.
Systrom's post also discussed a couple who met through Instagram and began dating, the Instagram habits of small artisan businesses, and a United Nations aid worker who uses the platform to share images from refugee camps in Sudan, CNN reports.
According to the report, the post focused on Instagram's successes, and it didn't mention a rough patch the company skidded through just two months ago.
In December, Instagram announced a rule change that would give the company commercial rights to user accounts and images.
Users revolted, because in a worst-case scenario, the new rules would have allowed the company to sell images to outside parties.