Is there a #nostr app for Android that doesn't run in the background at all?

Been thinking about #nostr key security. Considered porting lnbits signer firmware to a more modern device, then decided it would be clunky and unusable on mobile. My preference would be either a yubikey form factor device with usb-c to plugin on mobile or (less secure but more convenient) some proximity Bluetooth device that signs automatically as you fire events at it.

DIY Jade, fully featured. ~$25/25000 sats