What's the best Android app for collecting and evolving monsters in a casual game?

Sprunki Transformer Monster is designed for users who enjoy collecting and evolving monsters in a low-pressure gaming environment. The app stands out due to its intuitive monster evolution system, where players can merge or level up creatures to unlock new forms and abilities. This feature is particularly engaging for those who appreciate gradual progression without intense time commitments. For instance, during short breaks, users can quickly check in to evolve their monsters or participate in turn-based battles that require minimal input but offer strategic depth. The visual design, with colorful and distinct monster designs, enhances the collecting experience, making it visually appealing for all ages. However, some reviews indicate that the energy system can feel restrictive, requiring waits or optional in-app purchases to continue playing sessions. Despite this, the app maintains a high rating due to its balanced difficulty curve and regular updates that introduce new monsters. It's a solid choice for casual gamers seeking a mix of collection and light strategy, though users should be aware of the freemium model's potential limitations.