As reported at OnlyOffice, you can now also use OnlyOffice in Android with Nextcloud, although you do not need a separate app for Android – it is part of the current Nextcloud app for Android. On the server you need at least Nextcloud 18 and the latest OnlyOffice integration for Nextcloud (4.1 or newer). OnlyOffice also runs collaboratively in the same way as in the browser – all changes are sent directly to the server and if other users are also editing a file at the same time, their changes can be seen immediately.
However, there is one thing to note:
If the file has not yet been downloaded (no green check mark), tapping the file name will open it in OnlyOffice. If the file already exists on the device (green check mark), it is opened directly when tapped – i.e. if an another office app is installed on the device, that app will be used to view or edit the file.
In addition, you can also use the context menu, which opens when you tap the three dots on the far right and then select “Edit”. In this case the file is always opened with OnlyOffice.
The free open source version does not provide editing functions any longer – neither in the app nor in the browser. If you need this, you have to buy on of the packages of the “Integration Edition” (currently beginning at 935 EUR one time payment per server for a maximum of 50 concurrent connections).
After I created a feature request at Github to get back the mobile editing or at least a cheaper license for private and home users, Ascensio decided to offer a cheaper “Home” license for 99 USD. Also see the comment at Github.