This questions splits this question into smaller parts. Living without Google
So first of all I would like to find out, how I can move the 2 ICSDroid calendars to the Phone section. I think with doing this the read-only issue will be solved, too.
After adding 2 .ics files (click image to enlarge)
Feel free to post also alternatives to ICSDroid if there is something better. It does not have to be ICSDroid for the import.
I now solved with installing ownCloud on my server. It was not difficult and is easy to setup. Also it gives the possibility to enable even more features.
So in Thunderbird I just add the online calendar URL to the specific calendar. That's it. The only bad thing is that Thunderbird(Lightning) does not get the colors from the server. So you have to set them manually.
And on Android you need a special app like CalDAV which is really cheap and as well easy to setup.
Now you can use any calendar app like the of your Android. Planner Plus or aCalendar. This is totally up to you. I really like Planner Plus somehow.
For me this is a really good solution. Synching is working perfectly even with different users on it at the same time. You can also manage the rights the users have in your ownCloud which was impossible with the row ics Dropbox solution.
I also use the Tasks app of ownCloud, what is called the app OpenTasks under Android, which makes it pretty easy also to use tasks on Android.
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