diff --git a/.gitignore b/.gitignore
index 7ef70ad..f693c41 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,6 @@
 # Built artifacts
 /lstags
 /dist/*
+
+# Temporary "scratch" directory
+/tmp/*
diff --git a/Makefile b/Makefile
index 4493535..75cf775 100644
--- a/Makefile
+++ b/Makefile
@@ -22,10 +22,30 @@ package-test:
 integration-test:
 	go test -integration -v
 
-shell-test: build
+env:
+	env
+
+shell-test: build shell-test-alpine shell-test-wrong-image shell-test-pull-public shell-test-pull-private
+
+shell-test-alpine:
 	./lstags alpine | egrep "\salpine:latest"
+
+shell-test-wrong-image:
 	./lstags nobody/nothing &>/dev/null && exit 1 || true
 
+shell-test-pull-public: DOCKERHUB_PUBLIC_REPO?=ivanilves/dummy
+shell-test-pull-public:
+	./lstags --pull ${DOCKERHUB_PUBLIC_REPO}~/latest/
+
+shell-test-pull-private: DOCKER_JSON:=tmp/docker.json.private-repo
+shell-test-pull-private:
+	mkdir -p tmp
+	if [[ -n "${DOCKERHUB_PRIVATE_REPO}" && -n "${DOCKERHUB_AUTH}" ]]; then\
+		touch "${DOCKER_JSON}" && chmod 0600 "${DOCKER_JSON}" \
+		&& echo "{ \"auths\": { \"registry.hub.docker.com\": { \"auth\": \"${DOCKERHUB_AUTH}\" } } }" >"${DOCKER_JSON}"\
+		&& ./lstags -j "${DOCKER_JSON}" --pull ${DOCKERHUB_PRIVATE_REPO}~/latest/; else echo "DOCKERHUB_PRIVATE_REPO or DOCKERHUB_AUTH not set!";\
+	fi
+
 lint: ERRORS:=$(shell find . -name "*.go" ! -path "./vendor/*" | xargs -i golint {})
 lint: fail-on-errors
 
diff --git a/README.md b/README.md
index 6b97d50..97e277e 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,9 @@
 [![Build Status](https://travis-ci.org/ivanilves/lstags.svg?branch=master)](https://travis-ci.org/ivanilves/lstags)
 
-# lstags
+# L/S tags
 
 * *Compare local Docker images with ones present in registry.*
+* *Sync your local Docker images with ones from the registry.*
 * *Get insights on changes in watched Docker registries, easily.*
 * *Facilitate maintenance of your own local "proxy" registries.*
 
@@ -47,6 +48,12 @@ My CI server is connected over crappy Internet link and pulling images in advanc
 
 There is also special `UNKNOWN` state, which means `lstags` failed to detect image state for some reason.
 
+## Authentication
+You can either:
+* rely on `lstags` discovering credentials "automagically" :tophat:
+* load credentials from any Docker JSON config file specified
+* pass username and password explicitly, via the command line
+
 ## Install: Binaries
 https://github.com/ivanilves/lstags/releases