Memocamp Alternatives

Memocamp has been down since yesterday. Does anyone know some good alternatives?

I am interested in practicing mental calculation and also memory (for which there are alternatives). The memoriad simulator is there but I don’t like it’s UX (or having to run it on my mac)

Also, if anyone knows how I can contact the owner of Memocamp to fix it, it will be great. I don’t think he checks his emails which is a pity for a paid service.

EDIT: It’s back now. Still would be good to know alternatives if any

I downloaded Memoriad, to have something offline. I dont do the mental calculations part, but noticed they have some. Might be worth checking out