CellMapper displays advanced GSM/CDMA/UMTS/LTE/LTE-A cellular network information and can also record this data to allow you to contribute to our crowd-sourced coverage maps.
Download App here: https://play.google.com/store/apps/details?id=cellmapper.net.cellmapper
App code is not Open Source.
Please check up Orginal File string.xml under on /app/src/main/res folder. Copy file new directory (name 'values-fi' for Finnish, example) and put string.xml file there. Change then English term to your own language.
Please open Issues tab and create issue.