I've been using Swan. Per my instructions, I buy a little every day, but they auto-withdraw from my bank weekly. Then it takes about a week for the transactions to complete. Finally, they dump to a wallet I set up for them when my total exceeds their (I want to say no cost; I need to check) threshold.
It's automated end-to-end. All I do is approve the withdrawal when they send me an email.
I really need to double-check my fees, now that I think about it.