Our digital planners on many PDF editor apps, however we do recommend GoodNotes for IOS. There are are other alternatives you can use if your device is running on Android or a different OS.
GoodNotes 5 is our top recommendation for iOS devices. You may use this on your iPad, iPhone, and your iMac or MacBook. Syncing across devices is possible, provided you are logged in using your icloud account and are connected to the internet whenever you make changes. GoodNotes is a paid app (around $7.00), but you only need to purchase it once.
For Android, we recommend Xodo, which can also run on Windows. Our tutorials mainly focus on IOS devices, but we do have a basic video tutorial for Xodo users available on our Facebook VIP Group. Metamoji is also an app that runs on Android, however has limited functionalities compared to Xodo.