Once you set your PIN, write down and keep it in a safe place. In case of loss it will not be possible to recover it, and to use again MONEE you will need to reinstall the app, losing all your data.
Alternatively, you can:
- try all combinations of 4 numbers ... you only have 10 * 10 * 10 * 10 possibilities: D
- try dates for you significant or type sequences "1234"
- go to the safe place where you had kept it and recover the PIN