What you are asking for will take around 3 months to complete from start to finish, possibly more time depending on platforms. If you want a basic, unpolished iPhone/Android application, that is two different platforms. Additional platforms require more time to develop as each platform comes with additional requirements, bug fixes, and other considerations.
I'm being honest with you, if you're willing to pay for the development of an app, what you pay is what you get. Higher quality apps require more time to create and therefore are more expensive.
I'll offer an iPhone app and an Android app for $3000 dollars, deliverable in 90 days from the day bid is accepted. Feel free to message me for more details.
Payment will be $500 initial, and $200 dollars every 7 days until completion.