I need custom application which works WhatsApp api but with out limitations in the following way.
Send 1 message to all of my contacts at once with out selecting them one by one.
Contact list can be provided externally as excel , text or cvs file
1) read contacts in my contact address book and load/show only those who are also using Whatsapp program. A (multi select and select all) for those contacts who are found to be using Whatsapp. A text box to enter message (and if possible to attach files). A (send button) to finally send/broadcast the message to all the selected contacts in batches of 25 to be within the broadcast limit of Whatsapp for 2000 messages per day and then automatically change the sender number and continue. The messages will make use of Whatsapp's service. It can be a standalone program or a program that interface with Whatsapp's mobile apk to achieve this batch sending. any platform like windows,mac or android will be OK but as long as my goal is achieved, either is fine.