Use any hex editor apps that are available for android and change the value of HEX Dword to any amount you want.
Crowns HEX 7a 7f 3d 20 Dword
Coins HEX e8 db 85 6b Dword
If the codes doesn't work, it is possible that your android version is not compatible with the code I provided above.
Fortunately you can do it manually! To do it manually, just use search function in your hex editor app, enter your current Coins and Crowns value in DomiNations and search for it (choose DWORD) .
If you see a small list of results, example 10. Just edit the value of them one by one until you can find the real HEX!
If you see a large list of results, you need to change the value of current Coins and Crowns value in DomiNations by either consuming them or adding them. Go back to the list and find your new current Coins and Crowns value in DomiNations to the large list and finally you can edit the value.