This is awesome, and the game Bandai should have made as an official project. I've been looking for a Digimon VPet for mobile and you are doing a damn great job.
I do have some suggestions or ideas, of you don't mind reading them.
1: Lower Stress cool down
2: Increase move and item drop rate
3: Add a Nickname function
5: Add a Level Up function, and when you level up the Digimon gains random star boosts or +10 to each, to make battles more useful (Perhaps more stress means less stat boost, to make it evened out?)
Anyway, just a few ideas. Excited to see how far this game goes, keep up the great work! 馃榿