app.py

```python
import gradio as gr
import os
from gtts import gTTS
import tempfile

def text_to_speech(text, lang):
    with tempfile.NamedTemporaryFile(delete=False, suffix=".mp3") as fp:
        tts = gTTS(text=text, lang=lang)
        tts.save(fp.name)
        return fp.name

supported_languages = {
    "English": "en",
    "Korean": "ko", 
    "Japanese": "ja",
    "Chinese": "zh-cn",
    "Spanish": "es",
    "French": "fr",
    "German": "de"
}

with gr.Blocks(theme=gr.themes.Soft()) as demo:
    with gr.Row():
        with gr.Column():
            text_input = gr.Textbox(
                label="Input Text",
                placeholder="Enter text to convert to speech...",
                lines=5
            )
            lang_dropdown = gr.Dropdown(
                choices=list(supported_languages.keys()),
                value="English",
                label="Select Language"
            )
            btn = gr.Button("Convert to Speech")
        
        with gr.Column():
            audio_output = gr.Audio(label="Generated Speech")
    
    btn.click(
        fn=lambda text, lang: text_to_speech(text, supported_languages[lang]),
        inputs=[text_input, lang_dropdown],
        outputs=audio_output
    )

if __name__ == "__main__":
    demo.launch()
```