Show device high score or Google Play Games high score?

My game is pretty basic. When you lose, there's a minimalistic Game Over screen that shows both your score for the current round and your best score.

[That's Flappy Bird, not my game]

The predicament rests in the fact that my game allows players to use Google Play leaderboards if they so choose. This creates a complication for me if I want to preserve the minimalistic look of the Game Over screen. Which score should I show as their "Best"? The high score stored on the device, or the high score fetched from Google Play?

If I show the Google Play score, it will appear to disregard any high scores the player had achieved on their device before logging in. If I show the device score, it will disregard any higher Google Play scores. If I show the highest of the two scores (what I'm currently doing), it could confuse the player. If I sync up the two scores, it will cause issues if two people want to play on the same device but with different accounts.

I'm now starting to feel like I should only work with the device score, and let Google Play handle the rest. They can click the Leaderboards button to open the Google Play interface, and then they can see their high scores, weekly high scores, and what not. So let them go to Google for that. I'll deal with the local stuff.

I'm not sure what the "standard" is in these situations because I don't play a lot of mobile games. What do you think I should do?

That is a good question, I was wondering the same thing. How I did it - I submit the score to game after each game, This way user can see their best score by day, week and all time. If they are not logged in, that score does not get submit. For the best/high score I use the one stored on the device.

If you do come up with a better way, let me know.

That is a good answer. Knowing someone else is doing it this way definitely gives me something to work off of. I think I'm inclined to doing it the way you suggested. It seems to make the most sense all around. Thanks.

If you want that look and both options you could make buttons to switch between local and global highscores. Flappy bird was mostly about doing better than last time so it made more sense to make you compete against yourself. You should also see which one is more relevant to your game.