If you’re interested in helping out with the WordPress native apps, check out the side bar for links to the GitHub repositories. Each repository has a number of READMEs to help with getting you started. If you run into problems feel free to check out the #mobile Slack channel. We’re not going to be actively posting on this blog going forward.
If you want to keep up with what’s new in the apps, check out https://apps.wordpress.org/blog/.