Electrum is an easy to use Bitcoin client.

There is no waiting time when you start the client, because it does
not download the Bitcoin blockchain.

Optional dependencies:
zbar (enables scanning QRCodes)
python3-trezor (Trezor hardware wallet)

Please Note:
- Electrum 4.5.8 is the last supported version for Slackware 15.0.
  Newer versions need at least python version 3.10.

- However, it is possible to use an "AppImage" provided by Electrum at
  the URL linked below (or in the Electrum.info file). This also
  works on Slackware 15.0 as an option to run newer versions.