Neuxpower instructed me to download the latest version and I was able to install that. It is only a time-limited trial, but it helped me decide to go for your $15 offer to buy a lifetime license with free updates within the current major version.
However, clicking the link on https://sharewareonsale.com/s/nxpowerlite-desktop-coupon-sale redirects me to a page where I am asked to pay the full price of $50. The offer is said to be valid for another 31 days on your page. No coupon code is to be found there. So what´s the deal?