the information on the TinyCam site does give the details on setting up a router forwarding.
The basic issue is the cam is unable to send to anyone outside the router. your viewing the cam within the private wifi network. to go out you need to configure the phone and router with the port the cam is using. The manual shows 8083 but you may need a different number.
I use a cam at home and access it via the home router.
example
home router ip 123.44.12.1
home router wifi ip 192.168.1.10
ip address of configured cam 192.168.1.99
router port configured to pass to cam 8099
Generally the router will also need to forwarding information to be loaded .
example. Port 8099 ip address is 192.168.1.99
when a remote access is needed. the remote user enters ip 123.44.12.1/8099
the remote user then is passed to the cam via the proper address.
this is the manual link
Manual | tinyCam Monitor
Amcrest may not want any competition so they try to push to their product to the easiest IOS phone..
a secret they don't tell you is the home cam can be accessed via any browser including the one on the cell phone by simply using
http://123.44.12.1/8099
the browser will then simply connect to that address.
hope this helps.