What are some alternatives?
When comparing Lenka and Doom, you can also consider the following products
Carbon - Create and share beautiful images of your source code.
Quake - Quake is a series of first-person shooter video games released by id Software.
Hueless - High-quality black & white photos from your phone
Call of Duty - Call of Duty is a first-person and third-person shooter series by Infinity Ward.
RNI Films - Real film filters for iPhone photographers
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.