Editing by multiple users
Opening and editing the same file (on a sharepoint/OD4B site) in Excel app by multiple users, like it is possible in Excel online.
= 2016-12-05 =
Great news. If you have build 16.0.7426.1015 or later, you have the ability to co-author with others on files that are stored in O365 or OneDrive.com (you can both edit at the same time and not lock each other out of the workbook)
2016-05-13 – Good news, we’ve started work on enabling co-authoring in Excel for Android.