I'm a professional Android developer. I have over 30 applications developed and published on Google Play.
This task assumes mobile development of any complexity: starting from small (couple of weeks) to up to several months projects.
Task includes gathering requirements, writing technical task, development itself, publishing and maintaining.
Task isn't limited to developing itself. If necessary extra team members can be invited to join the project (designers, web developers, etc. ). Which means I can be primary point of contact for developing app, and app is developed fully from scratch. I have necessary Project Manager expertise in this area.
I start the work from estimating, and with big amounts of work I split it into deliveries. Each delivery is fully functional, which means on every stage of the work intermediate result can be fully tested and evaluated.
Additionally I can invite extra people to join the project if needed. Designers, wet developers, language experts, etc. Which means project of any complexity can be built from scratch, and I can lead this.