Instagram's activity status is similar to GPS and other online features that help you track other people's activity. Meaning it is flawed in a sense. For example, some users receive Snapchat's "someone is typing" notification when their friend has only opened the message. The reason for these irregularities on Snapchat is because the app is designed to pick up on certain characteristics and behaviors that assume you're online. So, a friend may have opened Instagram, then switched to another app or locked their phone and put it in their pocket, which means they aren't technically active on the app. Overall, the activity status on Instagram appears to be relatively accurate, but there is always room for error.