The android app is using Crittercism per the opening post asking for testers. But I'm not completely familiar with the workflow of Crittercism, should I be submitting the native Android crash reports as well? I don't want to double report a force close to the dev's if I don't have to.
You could if you'd like.
Crittercism is more for the auto aggregation of bugs so we can easily look at things like "give me the N most common crashes on the latest app version"
The native crash reporting does aggregation too, but what's nice is that you're able to put in data into it yourself. So, if you have a crash that we're having difficulty tracing down (something that doesn't really happen at the scale we're at right now) you could put in some custom text when sending your crash report along the lines of "Hey it's Steven, this is the crash I've been talking about on meta" which would help us pretty easily track it down.
For any regular crash I wouldn't worry about reporting it through the Play store, especially if it already has a corresponding meta thread since that means we definitely know about it. But if you want to help us track down a more rare crash or if you want to post a reproduce steps for a new crash on meta, feel free to report it on the Play store and also tell us the text you entered as the description for it.