"The Address Book for the 21st Century
Caret exchanges automated status updates with your approved contacts, such as call availability, calendar events, location triggers, local time and timezone information, etc.
The app transforms your static address book into a dynamic view of
your contacts' availability and status."
"Hound gives you fast and deep results to what you ask for, such as looking up the weather, placing a phone call, sending a text message, finding a hotel that matches your detailed criteria, navigating to an address, checking the stock market, searching and playing music, and even playing interactive games."
"No More Voicemail helps you stop your voicemail box from becoming full, and from needing to check or return messages at all, by sending your unanswered phone calls to endless ringing."
"The feature phone reinvented
KaiOS brings smartphone-like functionalities to affordable phones: the KaiStore for apps. Video calls over 4G. Mobile payments through NFC. Even dual-SIM support."
"WebCatalog is an open source desktop app which allows you to install and run your favorite web apps natively. Similar to the app stores on your smartphones and tablets, you can just open WebCatalog, install an app you like and start using it immediately. Those apps will stay on your Dock or Taskbar, notify you when you receive a new message or a call and more; or in short, improve your productivity significantly."
"Secure texts for Android
TextSecure encrypts your text messages over the air and on your phone. It's almost identical to the normal text messaging application, and is just as easy to use."