As SparkChess grew over the years, so have the different available platforms and payment options.
The SparkChess version you see on the main website is the free version. It cannot be “converted” to premium/full.
SparkChess (Lite) is the free version on Android and iOS. It can be converted to Pro by purchasing a subscription (previously, users could purchase individual features, but it was too inconvenient)
SparkChess Pro is a one-time payment version with all freatures enabled. It’s available on Windows, Mac, Android and iOS. It’s not updated as often as Premium Live.
SparkChess Premioum Live is the full-featured version you can play online, on any device.