This covers the case in which you have all the data in the desktop application. The Android application is just used to enter transactions on the go. From time to time, you sync the data with the desktop to keep it up to date. To do so, you'll have to export new transactions from the Android application and then import them from the desktop.
From the Android application
- Open the application menu and select Export... A new screen with the title Export Transactions will open.
- In EXPORT TO select where you want the exported files to be placed. For example, ownCloud.
- In FORMAT select QIF.
- SINCE will usually have the correct date, so you shouldn't need to change it (see this article about how this field works).
- Check Delete exported transactions, if you don't want to keep the transactions on the phone.
- Press EXPORT.
- A file will be created with the format:
<date_and_time>_gnucash_export_<book_name>_<currency>.qif. For example:
20161230_214456_gnucash_export_Book_1_EUR.qif. Note that, if you are exporting transactions with multiple currencies, you will get a file for each currency. The file name will be the same, just the currency part will change.
From the desktop application
- Go to Files > Import > Import QIF... The import wizard will open.
- Follow the steps of the wizard. When you are asked to provide a file, select the one just exported.
- Once finished, the new transactions will be available in the application.