There a helpful little course on advancing your typescript skills which was made by @GabrielVergnaud it is definitely worth checking out, even if you only complete the free chapters: type-level-typescript.com
Say what you want about wallets which take custody of your keys. If it wasn't for @CelsiusNetwork's app I would currently be tearing out my hair from losing nearly half a bitcoin due to the iPhone bricking after I transferred coins....
