App that identifies moves as Excellent/Good/Mistakes/Blunders I really like the analysis tool on chess.com that processes your games and identifies the Excellent and Good moves, as well as Mistakes and Blunders. It also proposes which move should have been played.

I realize it's probably based on a drop or increase in your piece advantage, but I really like this tool since I can clearly see what were my opponent's blunders or mistakes (as well as mine).

Is there an Android app that has similar features? The chess.com app allows me to analyse my chess.com games, but not to import a PNG and process it. Other analysis apps I've seen only return the "piece advantage score".
I would suggest starting at lichess.org. It has tools that let you (1) analyze a game that you play on the site or (2) import a game and analyze it.

The lichess.org analysis includes inaccuracies, mistakes, and blunders. It does not have excellent or brilliancy (! or !!) markers, but they provide a rationale for why they don't use those. You can decide whether their explanation suffices for your purposes. They use a centipawns lost or gained graph that seems to be a good indicator of the game state. And they often suggest better moves with the corresponding alternate lines.

They have an Android app at https://en.lichess.org/mobile that you can try out to see if it meets your needs. You can also try out their web site on a mobile device to see how that works, too. 

Finally, what I like about lichess.org is that they seem to have a great interest in having a clean, stylish piece and game user interface and they also seem to be actively developing, so if you have suggestions they may take a listen.

EDIT: Somehow I neglected to mention earlier that the site is free and the code is open source. Both are great if you want to save some money while learning chess and even possibly get interested in seeing how the site code works.