How to select multiple social accounts to post to from the iOS app
To schedule a new post from the iOS app, click on the + icon at the bottom of your screen. Once the composer is open, you'll see a + icon alongside the social account you already have selected. Tap the + icon to see a list of all your connected social accounts.
Tap on any accounts you'd like to include and then click Done at the top right corner.
Each of your selected social accounts will appear in the composer and you can now go ahead and craft your post!