If you can get it, I recommend the app called "Russian Alphabet in 3 Hours." It uses what it calls "contextual learning", going through the letters and putting them in context of use to help you learn them. You'd probably have to practice them as well after to make sure it stays ingrained, but I think it's a pretty strong introduction to the alphabet. And it's free, afaik; the only "string attached" is an organic ad for a related podcast that teaches more Russian and I think the podcast is paid, but I didn't go as far as checking that out.