On 3 July 2015 at 20:39, Craig Sanders <cas@taz.net.au> wrote:

my phone only rings about 3 times before diverting to voicemail,
so if (as is usual) my phone is in another room plugged in to the
charger, it gets diverted to voicemail just as i'm picking it up to
answer it. this is very annoying.

No idea about the app, but if you're using your phone providers voicemail facility, you can normally change the number of rings/seconds before diverting to voicemail - see this Wikipedia article

https://en.wikipedia.org/wiki/Call_forwarding#Mobile_.28cell.29_phones

I am on Telstra, and I can change the diversion time to 30secs by doing

**61*101**30#