The app is written with a game engine called Defold. I strongly recommend getting to know the engine a bit before jumping into the projects as that could be a bit overwhelming.
Start with doing a few tutorials from here they are all really good but for this project I think "15 Puzzle" and "Colorslide". I would recommend to do them all however.
Submit Pull Requests (PRs) to contribute to Pokedex5e. PRs can introduce new featuers, fix bugs or such.
- Never submit a PR that does more than one thing.
- Always reference existing issues covered by the PR.
- Individual commits should have informative commit messages.