Please try the following:
1. Try connecting to a different network..
2. Uninstall and delete any unused software or files and clear the data cache to create more space.
3. Try downloading the app through other platforms, as Google Play may have blocked the download.
4. Back up any important data (contact, text message, etc.), reset to factory settings and try again.
If the issue persists, contact the Nothing Support Team for further assistance.