If you have a lot of tasks, then when you first open Marvin on a new device, it might take a few minutes to sync. And when you open Marvin on a device that you've recently used, changes should sync up in a few seconds. This may take a bit longer, especially on mobile, depending on how many tasks you have and how long it's been since you opened Marvin. We have plans to improve this in the future!
You should see a sync indicator at the top-left of your screen while Marvin is syncing.
Sync definitely isn't working
If sync isn't working, the first thing to do is a sync health check. This can help you figure out if you don't have a connection to Marvin's sync servers (perhaps it's blocked by a work firewall) and similar issues.
The next step is to check your console for errors. Sending us any errors you see there can help us figure out what's going wrong.
Also try disabling any browser extensions or settings that are preventing 3rd party cookies, scripts, or requests (such as NoScript). Be sure to whitelist both serv.amazingmarvin.com and cloudant.com.
In many browsers you can click the lock icon in next to https://app.amazingmarvin.com in your browser's URL bar to see if something is being blocked by your browser:
And in many browsers you can look on the right side of your browser's URL bar to see which extensions might be blocking requests in Marvin: