https://github.com/doc-rj/smartcard-reader
https://play.google.com/store/apps/details?id=com.inoapp.car...
Other than that there are java cards in microSD format such as these
https://news.ycombinator.com/item?id=9625862
http://www.cardomatic.de/epages/64510967.sf/en_GB/?ObjectPat...
Then there's also a shaky area of pkcs11 proxies.