1. Open folder with your resolution (2560x1080 or 3440x1440). 
2. Put the two files into <path-to-game>. Then ingame select 21:9 resolution. 
3. Use on any DX9 game (often works, not always). But this upload was in support of 21:9 rendered cutcenes, on Assassin's Creed: Revelations 2011. 

Note: SoftTH file was created using Smooth Framerate option.