We have a small dev team working on 2 apps (A and B) concurrently. During one sprint we might need to fix some bugs from App A and work on some stories from App B. Sprintr seems to force us to segregate App A and App B so that we cannot plan a single Sprint, or see a single burndown chart, in one place for everything we're doing in that sprint. Should this be possible or are we just doing it wrong? Any thoughts appreciated.
You are doing it correctly.
The project is directly linked to your app, so is the sprint.
A sprint in sprintr is part of a single project and you can't combine the work for different apps in 1 sprint.
I would work in 2 sprints for the two products and shorten the sprint duration if working on both apps.