Dear,
Would be very usefull is you add a calculation point to begin descend.
Clould be somenthing like this:
Set the target altitude (by default nav target airport or WPT)
Set target altitud over groud (ex. 700 ft)
Set descend rate (ex. 500 ft/min)
System has Ground Speedy and current altitude, so is easy to calculare the distance to target where descend begins.
When target NAV DME is on carculateed distance, show an alrm indicating begin descend and rate.
Great APP!
Thanks