What app is missing from the Android ecosystem that you would find genuinely useful?

Hey all,

So, I've been reading up and such on Android development for a couple months now, and I'm itching to branch off on my own and write my own app from scratch. However, I've found the hardest part of app development is knowing what you're actually going to make.

Therefore, my question to you all is so: What do you feel is missing from the Android ecosystem? When have you gone "Oh, I wish there was an app for that!"? I don't want to make my first actual app too simple that it's devoid of any usefulness, but at the same time I want it to be simple enough for a first project.

Anyway, I look forward to hearing what you all have to say! Thank you!