Yes. As you know, each store has a separate admin panel, so if you run 5 stores and want to benefit from retargeting on each of them, you will need to install the app on each of the 5 stores separately. This way you can apply unique settings to each of the campaigns and ensure the maximum possible profit from each of them.
More useful info here:
- Can I use 2 or more retargeting apps at a time?
- Can I run 2 or more retargeting campaigns with RetargetApp?
- Does RetargetApp connect to other campaigns I’m already running?