This game has been $4.99 and $2.99 recently but 99 cent games seem to have a way to make us give away $1 pretty easily. 4.8 of 5 on the App Store with 250+ reviews. 2018 release. No IAP’s or any kind or ads. Offer good from September 6, 2019 to September 10, 2019.
Yeah, I already revived the game's thread here mentioning the sale. For a dollar it's a steal. I'm surprised this game hasn't had any more attention. Seems to be a treat for us, puzzle enthusiasts.