I think having a few samples of some strings (maybe "ok", "cancel", and a more complex string) would increase the number of purchasers. As it is now, I have no idea of the quality of the translation or even what languages are supported.
Languages: all 34 in the iOS and OS X. Including two variants of English, Chinese and Portuguese.
String examples (in Spanish):
"A connection timeout occurred." = "Se ha excedido el tiempo de conexión.";
"A fair night" = "Una buena noche";
"Importing ‘%@’" = "Importando “%@”";
"“%@” does not appear to be a valid email address. Do you want to send it anyway?" = "“%@” no es una dirección de correo válida. ¿Desea enviar el mensaje de todos modos?";
Other than that, looks like it could be useful.