It doesn’t look like it. It might be worth suggesting it to the man behind Language Transfer, he probably just doesn’t know about f-droid.

Yes, Language Transfer doesn’t have as many languages as Duolingo. Hardly surprising, since the entire system and all the language lessons were created by one man!

For me, the most important thing is to learn to think in the other language. Everything else follows from that.

Language Transfer makes a conscious effort not to get you to memorize things, but to internalize them and understand the system. That works perfectly with my own way of learning.

Language Transfer is much, much better than Duolingo for learning a language.

I am learning Spanish using language transfer after having learned four other languages in more traditional ways. Obviously, immersion is the best way to learn. But if you have to learn any other way, this is the one. Far, far better than Duolingo.

It’s made up of MP3s, usually about 10 minutes each. You just listen to them and respond to the instructor.

You can use SoundCloud, or YouTube, or the simple but practical smartphone app. The whole thing is run by one guy, and there is no charge but he asks for donations. I have been paying $10 per month on Patreon for several years now, and consider it well worth it.

You can learn French, Spanish, Italian, German, Greek, Turkish, and Swahili.

Using JavaScript to open a save or load dialog is not possible on Firefox. It lacks the methods showOpenFilePicker() and showSaveFilePicker().

All it can do is open a dialogue to load or save a file. The action must also be initiated by the user (e.g. clicking a button). It’s not randomly allowing a page to load and save on its own.

It is simply an HTML page with local JavaScript files. Nothing else. It has to run on as many platforms as possible, and be totally isolated from the outside world.

The best one is Language Transfer. Completely free (I’m a patron, though) and speaking as someone who has learned five languages aside from English, this is the best system outside of full immersion.

I’m working on an application right now that requires the ability to load and save data to the local file system. Firefox does not allow this, whereas Chrome does. The whole application runs from the local file system, so I don’t think there is much of a security issue.

But I actually do is test for the existence of the function to open the save or load dialog. That way, if Firefox does implement it, Firefox will work as well.

Language Transfer is hands down the best language learning system I’ve ever used. Completely free, although I have a monthly patreon donation set up.

It has 10 or 12 languages, although some of them only offer a beginner course. Still, not bad considering that it was all done by one guy!

Each course is done as MP3s with a conversation between the teacher and student. You can play them on YouTube, SoundCloud, download the mp3s, or use the extremely convenient app.