I've posted a new build for Subscription Tools in the downloads section (members only).

New Functionality Includes:-

• Source released.. !
• Added a period (days) dropdown to send reminders, so you may select the period of how many days until expiry. Note, it will only send 1 reminder ever for each subscription, it marks the receipt as having received a email.
• Added some further localization, although there are still some controls to go

Thanks again for all your feedback!