Thanks for clarifying! I tried that on my Android and I see what you mean. I believe that is because the yoga entry you are using is a general stretching entry that doesn't fall under the cardio or strength training categories the app uses. I will pass your feedback about that along.
I was also able to find a workaround you can use in the meantime if you'd like. Here are the general steps:
1. Add yoga as an exercise not listed on the website by clicking "Enter Your Own Exercise" under the search button.
2. Make sure to select the strength training category and also be sure to add it to your favorites.
3. If you'd like to enter the calories burned value that you typically see from SparkPeople, you can do that as well. Overall that total calorie burn doesn't appear to be much (it showed me as having 12 calories for 5 minutes), so you can probably estimate that with relative accuracy. Once you do this, the exercise shows under your favorites on the app.
5. The new yoga entry will now show under your favorites on the app :)
I hope this is helpful!