What's the easiest (and cheapest) customer loyalty program to use with Lightspeed POS?

I'm the manager of a bead & jewelry store in California. My boss & I have been discussing what our best options are for upgrading/replacing our stamp-card rewards program with a program that can be integrated with Lightspeed OnSite POS system. Many of the programs listed on Lightspeed's website work best with their Retail version, but we're not ready for the extra cost of upgrading our entire operating system, so we're hoping to stick with OnSite for now.

The three programs Lightspeed says are compatible with both Retail and OnSite are AppCard, Perkville, and ThirdShelf. What are some thoughts you have about working with any (or all) of these programs? Specific pros and cons? Price ranges would be helpful, since at least two ask that you call them to set up a demo before they'll tell you prices, which I feel is a waste of my time (I've already done it once with an independent company, and now they keep hounding me to call them/email them back). Any feedback is appreciated. Thanks!