Blockpass only stores a hash of your data, not the actual data.
Your information only exists in your mobile phone and in the server of the service(s) you have decided to share data with.
Blockpass provides a re-usable identity and does not keep users data.
You can store safely your identity in Blockpass mobile application and re-submit it later to other services
By deleting the app, all your efforts to get verified are lost.
By keeping the app, you can simply re-use data, images and even your certificates if the service is Blockpass-compatible.