Suggestion: keep track of which ones have already been shown in the current streak to avoid repeats? I did 100 of them, maybe 10% of which were repeats (I got Bellsprout four or five times on its own)
Currently, the application fetches random pokemon, which might explain why there might be repeats. However, changing difficulty levels lets application choose from broader range of Pokemons. Can you try that?
I just did another hundred (on ultimate), and got Marshtomp, Shellder, and Pawniard each twice.
Also, I got one wrong at one point (Misdreavus's silhouette was just an unrecognizable blob to me haha), but it didn't have me start over and instead just let me try the other options. Not sure if that's expected or not, but I figured I'd check, since it didn't give me a message telling me what was going on, so I thought the button wasn't working at first.
I'm still waiting to get either Voltorb or Electrode and have them both in the options. It would be literally impossible without viewing the actual image...