I know this is kind of off-topic, but I figured here is the best place to ask.
I’m trying to learn a little Spanish as well as Japanese, and can’t find anything similar to, or as good as, Renshuu.
Anki and Algo are ok for quizzing, but I honestly find them kind of unintuitive. And all of the major language learning apps (Bunpo, Memrise, etc.) are either lacking, require a paid subscription, or both.
I haven’t come across any other platform like Renshuu to be honest, but I’m sure there are some out there for Spanish. Depending on where you are, if you have a library card, you can get free access to language learning apps. I use mine with Rocket Languages which has a variety of languages, including Spanish and it’s very nice. You get to practice speaking a little, great grammar points and quizzes. I use it to supplement my Japanese studying. I get like 8 or 9 modules free which has multiple lessons, all of which should get me through N5. There’s also higher levels with more modules but not sure if those you have to pay for or not or if it becomes available once you finish the first level.