Android (4.0+): Hushed generates disposable, throw-away phone numbers that you can use for incoming and outgoing phone calls and text messages. The app is ideal for communicating with people you don't know, such as someone selling furniture on Gumtree, or a blind date you're meeting for the first time.
Hushed can be used for any scenario where you need to receive calls or text messages privately, or if you just want to organise them by topic. You can create phone numbers specifically to post publicly if you're renting a room or selling something, and corral all of your calls and messages together accordingly. If you're travelling abroad, you can buy a number in the country you're visiting so you can be easily contacted by locals. Each Hushed number comes with voicemail, so you don't have to dump those calls into your normal voicemail inbox. When you're finished with a number, just delete it, and it's gone forever.
Hushed also works in over 40 countries, and it allows you to choose phone numbers in any of those locations. Hushed numbers are good for seven, 30 or 90 days, and it will set you back $US1.99 each. The app is available now for free at Google Play.