Funnily enough I also never heard about Toucan before. I made https://vocabboost.online/ (which uses a similar idea, but for making languate tests out of webpages) and only then users told me that it was similar to Toucan.
There needs to be a completely offline version of it and that will be a killer. Even if it's a paid one.
My tactic so far, to force myself to learn, is to change the system settings to the desired language, which in turn makes a lot of the apps and websites default to that language. It’s a pain to look up words all the time but on my phone I keep the reverso context app and the Google translator always at hand. On my laptop I just Google it.