1. A method, comprising: determining an application library method for modification of an application library based on a configuration file, the configuration file specifying areas in application execution where instrumentation is desired, wherein the application library is compiled into bytecode designed for execution on a first virtual machine without access to an external mobile operating system instrumentation library; generating, using a first environment, a wrapper method for a system library method invoked at the area in application execution, wherein the wrapper method comprises: an instruction to invoke an instrumentation method in the external mobile operating system instrumentation library that is accessible by a second virtual machine associated with mobile operating systems; and modifying the application for execution on the second virtual machine by replacing an instruction that invokes the system library method with an instruction that invokes the wrapper method, wherein the second virtual machine does not have access to the system library method.