Why this happens
Willow works as a custom iOS keyboard. Sometimes iOS automatically switches you back to the default Apple keyboard, which makes it look like Willow “disappeared.”
How to switch back to Willow
Open any text field so your keyboard appears
On the keyboard, tap the globe icon in the bottom-left corner
Select Willow from your keyboard list
If Willow still doesn’t show up
1. Check that the Willow keyboard is enabled
Open Settings
Go to General → Keyboard → Keyboards
Make sure Willow is listed and turned on
2. Restart both apps
Swipe up and close the app you’re typing in and the Willow app, then reopen them.
3. Restart your iPhone
A quick reboot fixes most keyboard refresh issues.