Main features:
・Making an xlsx file on the iOS device.
・Exporting the file via email.
・No use of apis in file making.
(Press the green button to send xlsx file.)
Credits:
This application uses the following open source widely in the code.
1. https://github.com/kwandrews7/MultiDirectionCollectionView/tree/adding-sticky-headers
Copyright (c) 2015 Kyle Andrews
License(MIT):https://github.com/kwandrews7/MultiDirectionCollectionView/blob/adding-sticky-headers/LICENSE
2. https://github.com/MaxDesiatov/CoreXLSX
Copyright 2018-2019 Max Desiatov
Apache License Version 2.0, January 2004 http://www.apache.org/licenses/