Tumblr iOS post creation flow

So I’ve just downloaded Tumblr for iOS again, it’s been a while so I thought I’d give their post creation a go. It’s definitely an improvement over the mobile web version, and has many more features, being native and all. More than anything I want to try their tagging and mentioning features. When the text starts to overflow, the box expands and they scroll the entire view which seems reasonable. They have quite a lot of white space to begin with, making it feel approachable and easier.