You can back up your data and categories on Zeny to GoogleDrive, Gmail, Dropbox and so on, then restore it when you need to do it. It's also useful when you want to transfer your data into other Android devices.
You can only transfer data between iOS and Android versions using ZenyPremium.
This help explains how you can backup and restore your data using GoogleDrive.
(This help is made for Taxnote but basic is same for Zeny as well)
1. Settings => Data Backup and Transfer
2. Save to Drive
1. Open GoogleDrive app on Android.
2. Choose a Taxntote data.
3. Tap the option menu located in the upper right.
4. Choose "Send a Copy".
5. Choose "Import data into Taxnote".
6. It will open Taxnote so tap "OK". (Your Taxnote data of device will be overwritten.)