Video/Audio Editor app on Android / IOS

To create a audio/Video editing app on Android / IOS with only basic editing functions. 1. set multiple breaking points on audio track 2. play the audio between 2 breaking points. 3. save and share audio between 2 breaking points. 4. play at slow / fast speed 5. add subtitle / transcription along the audio track 6. save the project including all breaking points / subtitles / transcription 7. all customize playing by breaking points. e.g. breaking point A -> B- A -> C. Please propose your technical solutions and budget.