You don’t state which version/build you are running, see under HELP – ABOUT MONEYDANCE. For example I am running 2017.5(1639).
You don't state which version of the APP your Phone is running.
As a guess take a look at this article to see if it address your problem, if not post again see http://help.infinitekind.com/kb/older-versions/dropbox-connection-p...
In your first post you state “Also when I selected wifi, it suggests using DropBox, but the instructions are not accurate. It says to ad the Network Synchronizer Extension. Which doesn't seem to exist..”
I understand Monydance did offer the sync option wifi, but discontinued it a long time ago. Certainly, it’s not an option in 2017. If resetting syncing described below does not help the can you give more information at what stage of setting up sync and on what device you are seeing this message. Under FILE – SYNCING what syncing method have you selected?
First I would try resetting your syncing as follows.
If you have any transactions on your Moneydance APP that have not been sync back to Moneydance on your computer you will need to enter them manually into your computer or they will be lost.
On your phone with Moneydance shutdown on your computer click on “Disconnect” (if connected) under settings on your Moneydance APP and then close the APP.
Using the Dropbox app or website interface, delete the .moneydancesync folder in your Dropbox folder.
Then re-open Moneydance and wait for the .moneydancesync folder and its contents to be recreated in Dropbox. This may take some time. Watch the Dropbox icon and wait till it states “Up to Date”.
Open and reconnect your Moneydance iPhone APP to resync your data.
Detail of syncing can be found at http://help.infinitekind.com/kb/syncing-and-sharing-data/syncing-wi...