I started working sometime ago on a Google Authenticator-like App for KDE Plasma., titled "OneTimePass". This was in anticipation of Plasma Mobile - so was written in QML, and leveraged KDE Wallet (will not work if KWallet is not enabled).

(Note that I have not tested this on Plasma Mobile and imagine it will likely need some patching to work well on Plasma Mobile devices.)

Support is limited to TOTP (Time-based One Time Password - the most common used by Google Authenticator) at this point in time. If there's sufficient interest, happy to put more work into this to support others.

I didn't have a lot of time to stabilize this, but had some time over the weekend to fix up the QML layouts and get this into a usable state.

This comes with two components:

A UI App that will show all entries (upon clicking, saves the code to Clipboard). A KRunner invoked with otp ${searchTerm} (upon clicking, saves the code to Clipboard)

The UI App:

The KRunner:

Build notes are available at the repository (and copied below):

https://github.com/jimtendo/onetimepass-plasma

sudo apt install liboath-dev libkf5wallet-dev libkf5runner-dev libkf5service-dev libkf5i18n-dev