War of the tools! No. Not D. Trump vs. Piers Morgan...
Photoshop is dead! Long live Sketch! Yeah, so not quite dead... But in just one year, Sketch has overtaken PS to become the most used graphic design tool around. G'warn Sketch.
Notifications, Loaders, and Navigation!
Okay those are the main three - but go and read this because it's got some great examples, and nice best practices for you to think about!
Don't make life a chore for your users!
Choose a style of navigation befitting your content, and please please please, don't make them press every option to figure out what it does.