Android: Some apps grab you by surprise and leave you saying, "Where has this been all my life?" Drupe is one of those apps for me. With one swipe, you can choose which app you'd like to use to talk with a contact right now.
Drupe is a contacts app with purpose: who do you want to call right now, and how? The left side shows your contacts (recent, favourite, or all contacts), styled as chat heads. The right side has your favourite messaging apps, SMS, video chat, or the phone dialer. Drag a contact to the app you want to use, and you're ready!
Of course, you can customise the contacts, the apps, and the theme. There's even a built-in dialer. Drupe has a permanent floating icon, and even has a lock screen widget that makes it faster to start conversations.
Drupe (Free) [Google Play Store]