Badger Wallet for mobile phones now allow you to sweep SLP tokens from a paper wallet!
Get it: badger.bitcoin.com
https://news.bitcoin.com/cold-storage-and-bearer-bonds-how-to-print-an-slp-token-paper-wallet/
I wish @BadgerWallet could be active so that it can be retweeted to promote the wallet.
Being able to sweep tokens is groundbreaking!