Instagram has been testing this features in the last few months. They made it official and now they will allow multi-account support from its app. We will now be able to use multiple accounts from the same device. So glad that Instagram made it easier for users like ME to manage multiple accounts.
You just need to add the account from the settings menu and once its set up, just click the username on top of your profile and swap between them. Instagram new version will be released this week to both IOS and Android