Many seasoned veterans of World of Tanks Blitz well know a tool created by lltwox, which displays more information than WARGAMING’s own API: the Blitz Hangar.
The tool is based on the game’s own internal XML files, rather than the open API that WG offers to 3rd party developers. This gives it one advantage: it can show the differences between the current version of the game client and the upcoming one (from Opentest). You should also know that game files are now compressed with a WG proprietary algorithm (based on LZMA), and it isn’t so easy to access them without some additional hacking.
Based on the 8.1 preview changelog on Blitz Hangar, the new update 8.1 of World of Tanks Blitz will bring a huge wave of balance changes.