Tinqly is an Android app for composing ringtones. With generators, filters and controllers it provides for many modules which can be graphically connected to produce interesting sounds. Generators include oscillators, instrument samplers, and there is a melody module. As for the filters there are low pass and high pass filters amongst others. The controllers may work on an elapse time basis, allowing for dynamically changing ringtones. The app includes a reference, a manual and many examples.
Using the user interface also non-programers can create complex ringtones. Here a few screenshots:
Finished ringtones of course can be registered in the device as ringtones. In addition, they can be sent to other apps, allowing for example to exchange ringtones with other tinqly users. Inside the premium version the generated sound files can be shared with other apps.