A good challenge for the mobile web is to create a chat app that works just as good as the Slack or Twitter apps. Currently, getting a chat app's text input found in the footer, to float on top of the keyboard, and being able to control the app after a user taps into the text input is quite difficult.

In this example the chat input is within a footer that is position fixed on the bottom. It works ok when you tap the input, and the input stays on top of the keyboard. However, the header scrolls up out of view, which is not what Slack or Twitter native apps would do. Additionally, a chat app would not have a keyboard accessory bar containing the "Next/Down", "Previous/Up" and "Done/Close" buttons.