I'm thinking about an App I would like to sell at .99$ on Apple App Store. Not so much, but I would like to limit piracy (or at better avoid it).
What are your approaches or best practise in this field?
- Freemium (some features free, some others not) model?
 - Encryption of some client/server comunication?
 - Some sort phone detection (IMEI, whatever?)
 - Antipiracy code library (if exists)
 
I see piracy as a big concern for mobile developers, don't you?