Go to the App Store’s Today tab > user icon → Purchased and then search for Things in your list of purchases.Make sure that you are signed into the App Store with the same Apple ID that you used to buy the app originally.
Then go to App Store → Updates to download the update. Sign out of the App Store (not iCloud) and back in.On a Mac, open App Store → Updates and hit ⌘ Cmd R to refresh the page.
If you don’t see the new Things update in the Updates tab on the App Store, here are some things you can try:
As they have full control over the App Store, they are the only ones who can assist you with a resolution of this issue. If none of these steps help, please follow Apple’s own troubleshooting guidelines, or reach out to their support team.
If this didn’t help, proceed with the steps in the next section. Now try updating Things again through the App Store.
You can find it in the /Applications/Utilities folder.
You can also force quit misbehaving Mac apps using Activity Monitor.