I’ve enjoyed using Mango. It’s always been free but there’s a paid version now too. It dives right into useful conversation, but gives cultural context before, like formal/informal or when certain phrases are used. It has flash cards built between lessons to help with memorization and you can even record your pronunciation and hear/see the audio clip and how it compares to how you are saying it. It also has the ability to download lessons for offline use. I first used it because it was one of the only apps/websites that specifically taught the Levantine dialect of Arabic not found on other apps.