The variety has kept me looking forward to trying new things within the app. Each pack lasts either 10 or 30 days, and you choose if you want each session to last 10, 15, or 20 minutes. I always select 10 minutes.
There are five categories: Foundation, Health, Relationships, Performance, and Headspace Pro (less guidance during the exercise).
Each selection in the category has a fundamental exercise attached to it. For example, I'm currently in the Creativity pack from the Performance category, and it includes an exercise where I make an effort to focus on my breathing for a few moments before letting my attention drift.
After eight months, I still look forward to each new pack, but I've found that there is a lot of overlap among the exercises.