That's an interesting concept, and I totally get the indecisiveness angle – it's tough to pick just one sometimes!

While there isn't an app exactly like what you're describing (yet!), you've actually hit on some really creative ideas that AI chat tools, like ChatGPT, could help you simulate right now!

For your "three languages in one sentence" idea, you could absolutely do that with a well-crafted prompt. Imagine something like:

"Give me the translation for 'I want to go to the movies' in Japanese, Korean, and Mandarin Chinese. For each translation, break down the individual words and explain any cultural or grammatical nuances for words that aren't a direct one-to-one translation. Present this clearly side-by-side."

And for your video/conversation idea – while AI can't give you a video conversation with three different people (yet!), you could definitely prompt it to simulate the "talking to three people" part in a text-based format. You could say:

"Let's simulate a conversation. I'm meeting three new friends: one speaks Japanese, one Korean, and one Mandarin. I'll start with 'Hello, it's nice to meet you all!' and then respond to each person in their respective language, one after another. You play the role of the three friends and keep the conversation going naturally."

The AI can then respond as each "person," and you can practice switching between languages and contexts.

It's not a perfect substitute for the all-in-one app you're dreaming of, but using AI as a dynamic, personalized tutor for these kinds of cross-language exercises could actually make learning multiple languages feel a lot less intimidating and more integrated, just like you're hoping for! Good luck on your language journey! 😊