hello,
The top WhatsApp libraries are:
mgp25/WhatsApp-Tools
Bulk sender mgp25/WhatsApp-Tools
venomous0x/WhatsAPI
Whatsapp API for .NET
We can integrate it in an android app.
I have a real time experience to develop bulk sms,emails and whatsApp sender apps.
Get in touch with me.
I will deliver it at less time to you
Thanks