Hello, thank you for reaching out to Microsoft Q&A.
I understand that the Excel app on both your iPhone and iPad crashes or becomes unresponsive when you try to open it.
Several users have reported that the Excel program is unresponsive or freezing on iOS devices after the recent updates. As a workaround, you can turn off your Wi-Fi or enable Airplane mode when the app freezes. Once you regain access, you can reconnect to Wi-Fi or disable Airplane mode.
Another option is to close the Excel app from the recent apps section.
- Restart your iPhone or iPad.
- Relaunch the Excel app.
If the issue continues, go to Settings > Excel > Reset > Reset Cloud Settings.
Restart the Excel app.