SpeakBattery does what its name says - the level of charge of battery is shown is spoken so you can consult it in any situation safely.
Ideal for people who can not go without battery and want to be attentive to the general conditions of the unit. The program advises you to charge your device in certain loads for you to be quiet.
Enjoy. It is cheap and very useful.
Programa em Inglês. Para a versão em português, procure na AppStore por 'BateriaSpeak'.