Are you a tech-savvy hitman? A politician with state secrets to divulge (on a budget)? Or just looking to ask Pawn Stars if they have Battletoads one more time now that they've blacklisted your number? Well, good news - Hushed just launched for Android, and it allows you to buy disposable, anonymous phone numbers right from your smartphone.
There are limitations, though. You're charged to buy a phone number ($1.99 for the US, $1.99 and up for everywhere else), and once you go past a certain number of included minutes / texts in each account tier, you either have to pay again, or if you choose a pay as you go account, refill your balance. The $1.99 US number plan, for example, includes 20 minutes of talk or 60 text messages. I'm not sure if you're allowed to pick, or if that's just the amount of credit associated with performing those actions that many times. Alternatively, for $7 (or more) you can buy a pay as you go account with $5 of included credit. The pricing for usage, so far as I can tell, is not divulged until you actually start using the service. Which seems kind of shady to me.
Presumably, you're billed by the minute / SMS, and charged more for international calling (SMS is only supported in the US, UK, and Canada).
The service includes voicemail, and numbers last for 30 or 90 days, though lines can be extended at any time of your choosing. Numbers can also be "destroyed" (disassociated from your account) at any time, and you can have as many numbers as you like on your account.
Of note is also the fact that the service does not utilize a Google Voice-like call forwarding system, so you can make calls from any data-enabled device (eg, a tablet, if you so choose), not just phones. The full list of countries with numbers available for purchase can be found on the Play Store listing, below.