I think this particular situation is probably a bit unique - Balatro is made with the LÖVE game engine, where the game is written in Lua, an interpreted language which has a runtime package for mobile platforms. Balatro also happens to work quite well on the mobile form factor out of the box.
These factors put together made it possible to create the mobile port with not that much effort for a third party. All of them needed to be in place for it to work as well the next time.