Earlier this month, Instagram began testing the ability to add a combination of videos and photos to a single post, up to 10 altogether. The feature was very broken at the time, but Instagram has worked out all the bugs since then. Starting today, the feature will roll out to all Android and iOS users.
When importing a picture/video, you'll see a new button to select multiple photos and videos. You can pick up to 10 pieces of content, re-arrange the order, and edit each one individually. On the timeline, a blue dot indicates a gallery post.
I don't have this feature on my devices yet, so it seems to still be rolling out. You can get Instagram from the Play Store at the link below.
- Instagram Blog