The Labeling Bundle labels features with border length and optional additional attributes.
https://demos.conterra.de/mapapps/resources/apps/downloads_labeling/index.html
Simply add the bundle "dn_labeling" to your app.
Clone this project and ensure that you have all required dependencies installed correctly (see Documentation).
Then run the following commands from the project root directory to start a local development server:
# install all required node modules
$ mvn initialize
# start dev server
$ mvn compile -Denv=dev -Pinclude-mapapps-deps
# run unit tests
$ mvn test -P run-js-tests,include-mapapps-deps