By default, all activities on Baloonr are anonymous from beginning to end. You anonymously post a baloonr. You anonymously launch, pump, and explore baloons. The act of pumping up baloons is anonymous - no one will know if you pumped up their baloon or not. The ONLY time that a baloonr isn't anonymous is when you want your name associated with the baloonr (a simple check when posting the baloonr). The ONLY time that a baloon isn’t anonymous is when you want to claim it during the Done stage and link it with your name.
(See our tutorial on Exploring and Claiming Baloons.)