Hi,
I m subha, working as Android developer for past 2 years.
So I have experience on developing app like delivering service to automobiles and all type of vehicles and firebase integration for single chat and group chats and sharing type attachment like What's app.
I assure that I can provide you best Apps in Android & iOS & Web service - API part will also I can manage within time you mentioned.
We can also provide you free issue fixing.
Thank you.