sml FoE Tools is a free Android app designed to help players of Forge of Empires manage their Great Buildings. It allows you to calculate the costs of your Great Buildings and check if investing in foreign GBs is worth it. The app also allows you to enter sponsors, set favorites, and copy costs to your clipboard.

The app requires some familiarity with "The Arc" for it to make sense to you. It is a strategy game companion that supports EN, DE, FR, IT, and RU languages fully, with partial support for CZ/ES/HU/NL/PL/PT. However, the accuracy and up-to-dateness of the app data cannot be guaranteed. It is recommended to cross-check the values with the in-game values for safety. Use the app at your own risk.

Overall, sml FoE Tools is a useful tool for Forge of Empires players who want to manage their Great Buildings effectively. It is easy to use and provides essential features that make the game more enjoyable.