Hi! I'm Jens, and I've built the Spoiler Season app.
The preview season for a new set has always been exciting to me – new cards are previewed every day, and as a limited player, I am trying to think about whether or not the cards that are being spoiled will be good or not. For the longest time, I have wanted the ability to grade cards as they are being previewed – especially with the recent changes of more commons and uncommons being spoiled during preview season. However, there wasn't really a great way to do that. I've tried building spreadsheets, but for the most part, I was looking at newly spoiled cards on my phone during downtimes, and editing spreadsheets on the phone isn't fun. Moreover, even creating that spreadsheet took manual work, and even then I couldn't actually see the cards, only read the text.
That's why I've built the Spoiler Season app. The app pulls the cards available on the Scryfall API (massive thanks to the Scryfall team for their amazing work), displays them in an easy-to-use, sortable, filterable view, and allows grading them. Every day that new cards are spoiled, you can continue your grading process. You can even view the resulting tier list.
I've had a lot of fun using the app when testing it during the last few set previews, and I hope you find it as useful as I do.