===Why are we doing this?
History and dif pages are used by editors and readers to understand how an article has changed over time. For editors, these pages are integral for gathering context around notifications and are key elements in a variety of common workflows.
===User story
As a user of the iOS app, I would like to be able to see how an article has changed over time by comparing two different revisions of an article.
===Proposed designs
=====User flows
{F29862753 width=1200}
{F29862752}
=====Selecting a revision
**Click through prototype:** https://wikimedia.invisionapp.com/share/7JSR4PIXM2H
| History screen | History screen with 'compare' | First selected revision | Second selected revision | Attempting to select third revision
|--- |--- |--- |--- |---
| {F29853186 width=220} | {F29853012 width=220}|{F29853015 width=220} | {F29853042 width=220} | {F29853047 width=220}
| Zeplin: https://zpl.io/VQQ9wmm | Zeplin: https://zpl.io/bekLRnm | Zeplin: https://zpl.io/2ZnkWJE | Zeplin: https://zpl.io/bAW4MqP | Zeplin: https://zpl.io/2jYPG4r
=====Comparing revisions
| User education | Top of compare revisions / diff page | Scrolled down on compare revisions / diff page
|--- |--- |---
| {F29853859 width=220} | {F29853206 width=220} | {F29853210 width=220}
| Zeplin: https://zpl.io/2yWmdKK | Zeplin: https://zpl.io/VYoBN6L | Zeplin: https://zpl.io/25AwWOr