Paul Kaganer
Paul Kaganer
For this purpose (localization of tools in wmflabs) was developed especially framework - see https://tools.wmflabs.org/intuition/ The translations themselves can be made in translatewiki.net
(some context for my request: Your tool was recently added in the Russian Wikipedia as regular external tool in each history page) 
About translatewiki - see https://translatewiki.net/wiki/Setup_of_a_new_project