I read that there was a free focus stacking app available for the iPhone recently. I decided to download it to try. Essentially it is an app which will allow you to capture multiple shots of the same subject but with focus being adjusted by the app to cover the depth of field you would like to be in focus. Clearly this app requires the iPhone to be tripod mounted to maintain stability while it shoots the various frames for stacking.
Now although the app is free and will allow you to shoot the individual shots, the focus stacking is done by uploading the photos which you would like to be stacked over the internet to the company. They will then do the focus stacking and send the final result back to you. The App comes with 10 credits for you to try the focus stacking, and more credit can be bought in App.
But as I already have Helicon Focus to do the stacking for me, all I needed the App to do was to take the photos and then sent to my iMac through Airdrop. Then the rest is as how I would do focus stacking.