I have been using this app for several years now. It has a gorgeous user interface. It is well organized, and lovingly supported by the developer. It is regularly updated with new texts available for in-app purchase. I have seen continued reliability through the operations and functions. The only problem I have came across is when I decided to enable iCloud syncing on both my iPhone and iPad apps.
To recover the journals that I lost after enabling iCloud syncing I followed the steps described below. First I backed up the journals as-is on my iPad by emailing them to myself. Then I went into the settings app and disabled iCloud syncing. I then relaunched the app and my missing journals had returned! (Do not be alarmed if the journals you have created since enabling iCloud syncing have disappeared, they will repopulate once you reenable iCloud syncing.) Again, I exported the precious journals I thought had been missing by emailing them to myself (you will manually input these later after reenabling iCloud syncing). Once I confirmed receipt of my backup, I then reenabled iCloud syncing in the settings app. Upon relaunching the app, all of my post-iCloud-syncing journals reappeared and the missing journals were once again missing. At this point it was but a small chore to manually input the many valuable journals I thought I had lost from the backup I had emailed to myself earlier, YMMV.
For those that purchase this app, but want a copy of the Wilhelm-Baynes translation, this can still be done! It does require that you purchase the I Ching version of this app, also created by Flat Earth Studio (and probably available only in the US App Store). Once you purchase the copies of the books that you desire from the Wilhelm-Baynes translation in the I Ching version of this app, under help you can then sync those purchases to this app. This enables you to access these precious translations in this, the Yi Jing version of the app. The I Ching version of this app is available only in the US App Store. The Yi Jing version is the international version of this app. Due to licensing restrictions by Princeton University press, distribution is only allowed in the US version of this app, as far as I understand. Thus, this workaround may only work for US customers.
I still use yarrow stalks for my consultations and love the fact that I can manually input my journals into this app. This is an appropriately respectful and inspiringly beautiful way to bring your precious I Ching consultations into the 21st century!