OpenTTD built as a web application, with touchscreen interface.
https://pelya.github.io/openttd-touch-webapp
Build instructions:
Download and build Emscripten SDK, as described on their page: https://emscripten.org/
This build was compiled using Emscripten 3.0.0, but newer Emscripten version will probably work too.
Clone OpenTTD Android repo branch 12 (webapp code will eventually be merged into master):
git clone https://github.com/pelya/openttd-android.git -b 12
Build it:
cd openttd-android/os/emscripten
./emscripten-build.sh
You can use ./emscripten-build.sh debug
for debug builds, it compiles faster.
By default the script copies compiled files to /var/www/html
which is the default Apache2 web directory on Debian,
you can change the target directory using command:
./emscripten-build.sh release /path/to/your/html/files