If this is a development environment then development should be done under apps. What is the problem with your developers having the apps password? For dev environments it should just be changed post-clone.
You can create apps_readonly user so that they can have readonly access. But otherwise somewhere you will have to give them access for apps.
If you are referring to R12.2.x , there is a slight difference in creation of read-only schema when compare to 11i/R12 .
Refer following MOS : Create And Register CUSTOM Schema On EBS 12.2 (Doc ID 1929668.1)
-Chiranjeevi M A