Best Free way to do timed buys with GDAX?

[DrBitcoin]

I like how coinbase lets you buy $50 worth of bitcoin, once a week. If you want.
But GDAX fees are less and doesn’t have this feature, I understand you need to use the APIs with a third party software.

Can someone recommend a SIMPLE, FREE piece of software to do this? I’m not interested in elaborate trading features.  I just want to do a simple “buy x amount of bitcoin, every day, or week, etc”

Thanks