DeskTime is a time tracking app from Latvia with apps for all major platforms. It carries a deep feature set for managing time across many customers, and it also measures productivity, including where unproductive time is coming from.
The integration list is shorter than some competitors offer, but these are real integrations that use the other services' interfaces rather than browser add-ons: you can search Trello issues inside DeskTime instead of switching over to Trello. As a European alternative for time tracking, it fits agencies and consultancies billing several clients.