Is CalDAV-Sync open source Software?
Currently it isn't, but it is planned to make it open source once it evolves to version 1.0.
Update: Some parts are already open source. See open source status for details.
Why don't you make it open source right now?
Because it's not ready yet. Some parts of the source code are quite messy, it would be too embarrassing to publish it ;-)
How do I setup CalDAV-Sync for ...
Please see the list of Supported servers & services then select your server/service to see the set up instructions.
It doesn't sync! What can I do?
My accounts are gone when I reboot the phone!
You've probably moved the app onto the SD card. Android loads all sync adapters during boot. If a sync adapter is not found, a "clean up" method is triggered. This method is important to remove dead accounts when you uninstall a sync adapter. If you move the app to SD then it may not be available during the account check (as the SD card may be mounted at a later time) and your accounts will be removed. So the fix is: Move the app back to the phone.
Only One-Way-Sync seems to work, why didn't it sync the new events to my server?
Please ensure that you choose the right calendar in your Calendar App. When you create the event, there is a calendar selection field that may default to your internal or Google calendar (see Calendar selection fields). CalDAV-Sync won't sync events in your Google calendar. You can disable the other calendars in your calendar app, so they won't show up in that list (though, I've heard of a few phones still showing disabled/hidden calendars :-|).
My calendar app always defaults to my Google (or some other) calendar, how can I make my CalDAV/SmoothSync calendar default?
This is a front-end issue. If your calendar app does not have default calendar option try the free app aCalendar. This is a very good and free replacement for your stock calendar app and it features an option to set a default calendar.
What do all those account settings mean
Please have a look at CalDAV-Sync settings for brief explanation of CalDAV-Sync's settings.
I've a new self-signed certificate, how can I get the app to accept it without recreating the account
Just open the account settings and go to "Update password", then enter your password and proceed. The app will ask you if you accept the new certificate.
Can CalDAV-Sync sync tasks/todos?
Yes, it can. In version 0.3 task support has been added to CalDAV-Sync. Please install this free task app to benefit form this new feature: https://play.google.com/store/apps/details?id=org.dmfs.tasks
Why can't I change the URL of a calendar afterwards?
Changing the URL of a calendar is a difficult operation and not supported yet. As an alternative simply re-create the account. Have a look at Changing the URL of a calendar for a detailed explanation.
Does CalDAV-Sync support auto-provisioning? How does it work?
Please see auto-provisioning for an explanation of this feature.
My Motorola device does not sync automatically, I always have to sync manually
An user reported this is due to a default setting on some Motorola devices. Please see https://forums.motorola.com/posts/d276744989 for the solution.
Why is the open source release taking so long? Just push your code to github and you're done!
Unfortunately it's not that easy. I don't want to release any code that doesn't meet my own quality standards. I'm an independent developer and I don't want my customers to see that mess.
All I know about CalDAV, CardDAV, iCalendar, vCard and Android I learned during the development of these apps. This means the architecture is not always "optimal". Also there is a lot of dead or commented out code and workarounds. There's not much (up-to-date) documentation in my code and even less unit tests. Definitely not the code I want to make public.
Currently I'm rewriting large parts of my code. All the new parts become open source as soon as they become usable, well documented and at least for the most important parts there are some unit tests (see Open source status). However, that is a lot of work and takes much time. Speaking about time: On an average day I get about 20-30 emails. All kinds of requests and bug/error reports. Many of those mails take a few minutes to think about, investigate and respond. As you can guess that slows down development. Beside the open source release I still have to spend some time for tests, new features and bug fixes (although the app works well for most users, there are still several issues to fix for others).
My phone is rooted / I have a custom ROM installed and your app behaves weird.
Custom ROMS, like CyanogenMod may have special privacy apps ("privacy guard", "PDroid", etc) which can restrict the permissions of an app. This is a useful feature e.g. to prevent free apps from loading ads but also causes problems for legitimate ones. Please make sure that you have given our app the necessary permissions.
It looks like you have disabled the app "Calendar Storage", which is the calendar database and thus necessary for our app to sync. Please open system settings and go to Apps->Calendar Storage and make sure that this app is installed and enabled. In case you can't find the storage it might help to reset the settings of the app manager.
I have Two-Step Authentication enabled for my Apple account and can't login.
You probably need to set an app specific password. Have a look at Two-Step Authentication for iCloud.