TomNuki

So I want to play HGSS/Platinum but I have a really difficult time getting into them because of the absence of the gen IV styled exp share. This is because I don't have a lot of time to individually grind up Pokémon due to school and sports but also because I simply don't like grinding. Are there any rom hacks (that don't change the core game of HGSS/Platinum or change it too much) that would add this? If not are there any tools that I could add it in myself?