I had been looking for a Tarot deck app for a while before I stumbled across her apps. I just wanted something quick and clean that could generate cards on the fly, which turned out to be a more challenging task than you might think. I had another one before, but it was gummed up with ads and was just a mess. (I don't remember which one it was, but even if I did, I don't think it's generous to badmouth a free app that was only mediocre.) For a while, I was using a random number generator. Golden Thread and Luminous Spirit Tarot are both what I wanted, plus more. (In a good way, not in an OPTIONS OVERLOAD way.)
Golden Thread is targeted at beginners. You can draw a daily card, and there are also spreads: one-card, three-card, and Celtic Cross. The single-card reading was perfect for my "I just need to draw a random card on the go" needs, and I'll be using it for that for the foreseeable future. It also helps you track a lot of neat Tarot data about yourself: how positive/negative your readings have been over time, the most common card keyword that's come up, etc.
The Luminous Spirit app is more intermediate focused and assumes you already have a solid working knowledge of the Tarot (though keywords are always available for each card, plus its reversal). Instead, it connects your readings to lunar cycles. You set an intention for each cycle, and then at each new phase of the moon, there's a different reading.
Each app uses a Tarot deck that has a physical, printed equivalent (hence my use of the "deck lust" tag here). The apps are free, and are free of ads. It's the sale of the physical items that helps support the apps. (And Gong's enthusiasm, natch.) I don't know how much I like the aesthetic of the Golden Thread deck, but I might very well pick up the physical Luminous Spirit deck:
This is a really well designed app, and I appreciate that they use original decks instead of just using the Waite–Smith deck. I admit that it wasn't until I did some research into Pamela Colman-Smith that I really appreciated the Waite–Smith deck, but now I'm totally onboard with it. My beef with Tarot apps using the Waite–Smith deck is more how it usually indicates a sort of lack of effort—just grab a public domain Tarot deck with easy-to-read images and go! No original decks, no recent decks that would mean paying licensing fees to artists or estates. (Of course, not every app or software with a more unique, modern deck is necessarily paying its artists. I recall a sketchy app ripping off a deck from the Magical Realist press.) But it's that extra attention to detail that makes an app really stand out, and that's why I think I'll continue to use it for a long time to come.