Hello,
If you are adding custom images, make sure to change "Position" to "Center (contain)". You can do it in the Edit dial window / Visual.
I know some things are not as intuitive as it should be. I will be releasing new version next week that should simplify things :)

Best regards,
Juraj Mäsiar

Hello,
Right click the group name and select "Edit group" (or from the main menu). There you can make group scrollable, add more rows or columns to fit more dials.
I hope this helps!
Best regards,
Juraj Mäsiar

Hello,
I know some things are not as intuitive as it should be and visuals are basic..., but there is many options and you should be able to tune it into your liking.
What you were probably looking for was the "Edit group" window (when you right click group name) where you can change number of rows / columns and even make the group scrollable to fit more dials.
The synchronization should work without any issues across devices and browsers, just make sure you are logged in the same account.
Regarding most-used dials, yeah, this is indeed missing since there is no tracking of user activity. I will try to implement something something for it in the near future.

Best regards,
Juraj Mäsiar

EDIT:
Regarding your question - the synchronization is automatic, just login to the same account on all devices:
https://group-speed-dial.fastaddons.com/
I hope this helps :)

Hello,
The synchronization is not paid :).
There is only few Pro features, all listed here:
https://github.com/fastaddons/GroupSpeedDial/wiki/PRO-version-features

Most of the features including all Cloud synchronization and backup is forever free!
Best regards,
Juraj Mäsiar

Hello,
Could you describe what exactly is wrong?
I'm preparing new version now so if there is something I can fix, please let me know.
Best regards,
Juraj Mäsiar

Hello,
The thumbnails are created from previews, so yes, without internet you won't get previews.
But once you get online, you can reload them all from the main menu.
And if you really want to stay offline 100% time, you can load individual thumbnails locally from the drive.
Best regards,
Juraj Mäsiar

Hello,
Make sure you are using at least Firefox 60. Also Android is not directly supported - but once you create cloud account, you can access your dials through cloud even on android.

Best regards,
Juraj Mäsiar

Hello,

Just don't panic. There is a good chance you can still get to them.

First, check the History - in the upper right corner on the dials page. This can be related to issue with downgrading Beta or Nightly versions, see this article:
https://www.ghacks.net/2018/08/06/dont-downgrade-firefox-63/

If you don't see backups in history, maybe you have created cloud account or have a backup file exported?

If you see any error on the dials page, please let me know - you can contact me directly to my support e-mail.

Most of these bugs is related to some Firefox bugs. My add-on cannot loose data by itself... Also it's used by 50k users so such issues would be reported by many others.

Have a nice weekend.

Best regards,
Juraj Mäsiar

Hello,

Just don't panic. There is a good chance you can still get to them.
Please contact me to my support e-mail. I can assist you with the fix. Don't forget to mention your add-on version, Firefox version and operating system you are using.

Best regards,
Juraj Mäsiar

Hello,
This is a Firefox bug I've reported here:
https://bugzilla.mozilla.org/show_bug.cgi?id=1462580
It will be fixed in Firefox 62, scheduled for release in 4 weeks from now.

Best regards,
Juraj Mäsiar

Hello,

In urgent cases like this, please contact me to my support e-mail (I'm trying to reply asap).
This issue was caused by a rare Firefox bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1478602
And it should be fixed after upgrading to the current version 10.0.
Also your dials are not lost, only thumbnails are not visible.
And to prevent loosing your dials, make sure to either create a manual backup in the Options page or by creating free cloud account.

If the problem does not disappear after upgrading to version 10.0, please write me!

Best regards,
Juraj Mäsiar

Hello,
Please try to upgrade to version 10.0 that fix some rare issues.
If the problem does not disappear after upgrading to version 10.0, please contact me to my support e-mail.

Best regards,
Juraj Mäsiar