iOS/Android: Gliph is a service that generates anonymous disposable email addresses for when you don't want your real email address exposed. The app allows you to send secure, encrypted messages to other Gliph users, or send and receive private emails to an online seller or online dating prospect.
When you launch the app, instead of a username you select a "gliph", a series of symbols that represent you to other users. Gliph then asks you for details such as your name and email address which can be associated with your gliph, but if you want to stay anonymous, you can skip them. From here, you can send encrypted messages to other Gliph users -- all you need is their gliph.
If you want to send anonymous emails through Gliph, you'll have to select a "cloak", a randomly-generated email address to hide behind. Once your cloak is created, you can email from inside the app, and any replies are sent to the address associated with your gliph. Your anonymity doesn't end there though -- if you reply to the message, even if it's at your desktop computer, it's routed back through Gliph so your anonymity is preserved.
Sure, you could sign up for yet another email address to stay anonymous, but Gliph addresses give you control over how long the address lives and how much of your actual information is exposed. You get one cloak just for signing up, but to get more you'll have to invite friends to use the service. Encrypted messages between Gliph users are completely free.