I remember a text message activated sms bomber. You ran a server at your house, and basically you text your email, and it would then automatically start bombing based on the text.
The text would be something like start -n 5123548944 -t 50000 -c "lolspam"
A bunch of parameters like that. So its not android specific, and not even an app. But any phone can do it. I just dont remember where I found it, but I can probably get again, if I cared.